IC 3000 is most likely a defect on the Bruce plate which Stewart examined. Even though there is a very faint spindle near Stewart's position, it is too faint and too small to have been recorded on the Bruce plate. It also does not match Stewart's description: "F, indistinct, * like, but poss. defect, susp." ===== IC 3003 is CGCG 187-011. As noted with IC 2993 (which see), Javelle misidentified his comparison star. Unlike I2993, however, CGCG has got the correct number on the correct galaxy for I3003. ===== IC 3006 is probably a plate defect. It was found by Royal Frost on a four- hour Bruce reflector plate taken at Arequipa, and was also recorded nearly 30 years later by Adelaide Ames at the same position, on the same plate. There is nothing near that position but a star about an arcmin northwest. Frost's and Ames's descriptions make an interesting contrast: Frost says "R, bM, magn 15", while Ames has m = 16.2, maximum diameter 41 arcsec, ellipticity (diamin/diamax) = 0.6, and a "class" that decodes as "irregular, bM but no N". All this is consistent with a description of a small plate defect. We can someday check the Harvard plate to be sure -- if the plate is not thrown out in the meantime (see e.g. B.E. Schaefer, S&T 105, No. 3, p. 42, 2003). ===== IC 3009 is probably a defect on Schwassmann's plate. There is nothing near his position bright enough to match his description ("pB, cS, fig? dist"). ===== IC 3011 = NGC 4124 = NGC 4119 (which see for that story). The position given by Schwassmann for the galaxy is virtually identical to its NGC position. I do not know why he did not make the connection between the two, nor do I know why Dreyer did not also catch the identity. In any event, the two numbers clearly refer to the same galaxy. ===== IC 3017. Nearly all the modern catalogues follow CGCG in assigning the number IC 3017 to the brighter, southern of a pair of faint galaxies northwest of the center of the Virgo Cluster. This, however, is probably wrong as this brighter galaxy is likely to be IC 3018 (which see) with a 30 arcmin error in its declination. The fainter galaxy is almost certainly IC 3017 -- Frost's nominal position is closer to this object. Adelaide Ames, working from the same plate as Frost, agrees; she adopted his position for the entry for this galaxy in her Virgo Cluster catalogue. ===== IC 3018 is probably the brighter, southern-most of a pair of galaxies found on a Bruce refractor plate by Royal Frost (the northern is IC 3017, which see). However, Frost made the declination 30 arcmin too large; there is nothing at his nominal position which Dreyer copied correctly into the second IC. The mistake was caught by Adelaide Ames while compiling her Virgo Cluster catalogue from the same plates that Frost examined. She words her note very cautiously (did she ever meet Frost?) and does not give the IC number in her table. However, I am pretty well convinced of the identity, so adopt it without reservations. ===== IC 3026 must be a defect on the 1-hour Harvard plate, number 3703. There is nothing in its position and Stewart notes that IC 764 is "p 0.3 min, n 11 arcmin" which is correct. Stewart also lists IC 764 in his table where it has similar offsets (0.4 minutes west, 12 arcmin north), so it is clear that he has the position of I3026 correct. For the record, Dreyer correctly copies Stewart's position and description into the second IC. All this can be checked if the plate still exists at Harvard. ===== IC 3027 is a plate defect. Found by Royal Frost on Bruce plate number 6718, it was picked up again by Adelaide Ames for her Virgo Cluster catalogue -- but dropped into a footnote where she identifies it as a defect. ===== IC 3030 must also be a plate defect, though it fooled Ames, too (see IC 3027 which did not) -- there is nothing near the position given by Frost and Ames but a very faint, very small galaxy that would not have made it onto the Bruce plate. ===== IC 3035 = NGC 4165, which see. ===== IC 3045. Like IC 3009, this is probably a defect on Schwassmann's plate. There is nothing at all at his position, let alone anything that matches his description "pB or pF, cS, N s M, N = * 10.5, S N pt" ("pt" means "pointed"). The mention of the bright eccentric nucleus especially reminds me of some of the blemishes that regularly appear on the POSS1, especially near the edges of the plates. ===== IC 3048 is probably the western of two stars near Schwassmann's position. His positions are systematically too far east by about 0.3 or 0.4 seconds of time and about 2 arcsec too far north. Taking these offsets into account leads to the western star. However, his standard deviation is around 5 arcsec in both coordinates, so it is not implausible that he actually saw a blended image of both stars on his plate. Unfortunately, since the plate can not at present be found in Heidelberg, we can't check this or any of the other missing "nebulae" that Schwassmann found on it. ===== IC 3049 is perhaps the southeastern of a pair of galaxies. Frost calls it "R, planetary?, magn 16" which will make it very small and faint in the grand scheme of things. I suspect the southeastern as it is a fairly compact elliptical with a bright nucleus, and would show up better on Frost's plate. However, the northwestern object, a low surface brightness IBm pec, may well be blended with its brighter neighbor on the plate. So, I've chosen the pair itself as the IC object, but give the individual positions, including one for a bright knot (or superposed star?) also involved in the image. Short of looking at the original plate, this is probably the best we can do. ===== IC 3050 = NGC 4189, IC 3051 = NGC 4193, and IC 3064 = NGC 4206 all appeared in Schwassmann's list of nebulae in the Virgo Cluster. Their positions are all very close to the NGC positions, so I'm pretty sure that neither Schwassmann nor Dreyer checked the earlier catalogue closely before listing these as new nebulae. There is no doubt about the identities; the positions and descriptions are too close to question. Adelaide Ames was the first to suggest all three identifications in her 1930 Virgo Cluster catalogue. ===== IC 3051 = NGC 4193. See IC 3050. ===== IC 3056 is most likely DDO 114 = UGC 07249 with a one-degree error in its declination. There is nothing at Frost's position that he could have picked up on his plate (the galaxy that Glen Deen suggests is much too faint and small to have been seen on the early Bruce plate). The identification was first suggested by Adelaide Ames in her 1930 monograph and catalogue of Virgo Cluster galaxies. Though the position angle is a bit off Frost's (he says 50 degrees, Ames has 60 degrees, and I measure 67 for the main body of the galaxy), the position is indeed exactly one degree south of Frost's nominal place. His brief description is appropriate, too: "Streak, E 1 arcmin at 50 degrees." ===== IC 3057 may be ESO 267-G036, but that is well off Stewart's nominal position. Also, the galaxy is a low surface brightness, late-type spiral, while Stewart's description reads "cF, S, R neb or defect, susp." Finally, the Bruce plate was exposed for only one hour rather than the usual four hours for deep sky-limited plates at Arequipa. So, I3057 is most likely, as Stewart suggested, a defect. ===== IC 3064 = NGC 4206. See IC 3050. ===== IC 3067 = IC 772, which see. ===== IC 3070 is a star northeast of the center of NGC 4206. Schwassmann's position is very close to the modern position. ===== IC 3071 and IC 3072 are stars near NGC 4207. Schwassmann's positions are good enough to unabiguously identify them. ===== IC 3072 is a star. See IC 3071. ===== IC 3076 is a star at Schwassmann's position. Even though Ames declared it "Not found" and Wolfgang pointed at a faint galaxy, Schwassmann's position is within five arcsec of the DSS position, and his description ("vF, vS") from the 6-inch plate is appropriate. ===== IC 3083 may be the galaxy that Wolfgang and I have noted in the position table. It is just 3 arcmin south of Frost's position, and matches his description (copied exactly into the IC). We need to look at the Harvard Bruce plate to be sure, however. ===== IC 3085 is a star, the western of three nearly equally bright stars forming a triangle. Schwassmann's position is good enough to clearly identify the star he measured. ===== IC 3086 is a double star. Schwassmann's position is good. ===== IC 3087 is two stars, rather widely separated, but in the correct position angle to match Schwassmann's description ("F, pS, like a line, 30 degrees"). Schwassmann also has a separate listing for NGC 4222, which he has at the correct position angle (58 degrees), so IC 3087 cannot be identical to this as suggested in CGCG and MCG. ===== IC 3088 is a star. Schwassmann's position falls within 10 arcsec of the star, and his description (vF, vS, li[ke] * 14) is appropriate for it. Wolfgang takes another star 25 arcsec north as the IC object. While I feel that this is less likely, it is possible. It may be that both stars are involved in Schwassmann's object. We'd have to look at his plate, but it may no longer exist. ===== IC 3090 is a double star. Schwassmann simply says "vF, S", and his position agrees in RA with the southeastern star, and in Dec with the northwestern. ===== IC 3098 = NGC 4235. There is a possibility that Schwassmann did not include the NGC number in his list because of the confusion over NGC 4223 (which see) and NGC 4241. However, I think he simply overlooked the NGC number in this particular case. His position agrees with the NGC position to within 6-7 arcsec, and his description matches that for N4235 very well. So, while the two "different" objects are clearly the same, both Schwassmann and Dreyer missed the identity, and we now have an IC number on the NGC object. ===== IC 3102 = NGC 4223, which see. ===== IC 3103 is a star. Like several others in Schwassmann's list, he notes that it is "li[ke] * 13." Since it is the only object in the area of his position, the identification is secure. ===== IC 3104 is a nearby dwarf galaxy found by Frost on one of the Bruce plates taken at Arequipa. It is well-resolved on the IIIa-J southern sky survey plates, and matches Frost's description well. Because of its far southern declination, its RA is not well-constrained, at least numerically. Also the galaxy also has no nucleus, so its position is usually taken as the center of the "bar". ===== IC 3106 is another star mistaken for a nebula by Schwassmann on his plate taken with a 6-inch telescope. Though he claims the nebula is elongated in PA = 95 degrees, this must be the result of a plate defect of some sort. Remarkably, there is a galaxy about an arcminute distant with the correct PA. However, it is too faint (SDSS makes it 17.0 in their "g" band; this is around 17.2 or 17.3 in B) to have registered on Schwassmann's plate, so the star is almost certainly the correct object. ===== IC 3109. CGCG has misidentified this object. It is actually the brighter, south-preceding of two galaxies, CGCG 069-131, not the fainter, north- following, CGCG 069-134. Frost's position is closer to the brighter object, so there is no question of the correct identification. ===== IC 3113 = NGC 4246. Schwassmann's position is within an arcminute of the NGC position. But given that that position derives from a single observation by WH, it's possible that neither Schwassmann nor Dreyer really believed that the object seen by WH existed (see the NGC note and my comments under NGC 4246 for more). It's just as likely, though, that both cataloguers simply missed the identity. I think that is what happened with IC 3098 (which see) = NGC 4235. In any event, the two numbers clearly point to only one galaxy. ===== IC 3114 is a star. Schwassmann called it "cF, vS, li[ke] * 12-13", but there is no nebulosity associated with it on the POSS plate. ===== IC 3115 = NGC 4241. See NGC 4223 = IC 3102. See also IC 3011 and IC 3098 for more about Schwassmann's list of new nebulae. ===== IC 3117 is a double star at the correct orientation (about 30 degrees) to be Schwassmann's object. He calls it "eF, S, l[engthened] 30 degrees". ===== IC 3123 probably involves a defect on Schwassmann's plate as well as the 10th magnitude star at his position. His description could go either way: "neb or *, dist, alpha delta :". ===== IC 3124 is a star. I suspect that Schwassmann's plate has a defect superposed as the star is relatively faint. ===== IC 3125 is a star close to Wolf's position. It is easily visible on the print of the original plate. ===== IC 3128 is a double or triple system, perhaps including a third (or fourth) galaxy to the southeast. The main component (VIII Zw 180.2) appears to me to be a bright nearly stellar object with a plume to the southeast superposed on a fainter galaxy just northwest. Zwicky has yet another galaxy further on to the northwest. Neither this northwestern galaxy, nor the one to the southeast, appear to be interacting with the peculiar system in the middle. ===== IC 3129 is a star about 8 arcsec south of Schwassmann's position. ===== IC 3130 involves at least two stars, and probably a defect as well. It appears on Schwassmann's plate as "eF, pS, ?, 140 deg, li plan li". The last phrase decodes to "like an asteroid trail." The nominal position is between the two stars, and there are two other stars in the area which may also be part of the object that Schwassmann thought nebulous. ===== IC 3131 = IC 3132, which see. ===== IC 3132 = IC 3131. Schwassmann's two positions are only ten arcseconds apart, not much larger than his standard deviation. Since he found the galaxy in two separate zones, it seems likely that he simply did not make the connection between the two listings, even though they ended up adjacent to each other in his table. ===== IC 3133 is most likely the wide triple star at Schwassmann's position. It matches his description ("eF, S, dif, alpha ::, delta :") well, so I've taken it as his object. ===== IC 3139 is a star close to Schwassmann's position. It is typical of some of the objects near the plate limit that he simply calls "eF, vS". His position, aside from the systematic offset (see IC 3048 above), is good. ===== IC 3142 is probably the brighter of a pair, though we can't be sure without checking the original plate -- Frost's description ("R, bM, magn. 14.5") is not very informative. ===== IC 3145 is a star. I've not yet looked for the object on the print of the original plate, but Wolf's position is good enough to be unambiguous. The only other possibility is a plate defect. ===== IC 3147, like IC 3142 (which see), is probably the brighter of a pair. However, it was found by Schwassmann rather than Frost. On the 6-inch plate, Schwassmann describes it as "vF, vS, like a star, probably nebulous", and puts the position between the two galaxies. Could there be a defect involved, too? So, while I'm inclined to take the brighter galaxy as I3147, I'm not at all sure. ===== IC 3158 is perhaps the star that I've flagged with a colon in the table, though there may well be a plate defect involved, too. Schwassmann's description reads "eF, cS, ??, alpha ::, delta ::". The double query means that Schwassmann was not sure of the object's reality. Combined with his uncertainty about the position, the fairly bright star is only a possibility. Indeed, Wolfgang has taken another fainter star to the north as the IC object. This could be right, too. Adelaide Ames and Dorothy Carlson have simply said that the object is a star, but we do not know which one they were looking at. It's a shame the original plate has gone missing. ===== IC 3160 is another star in Schwassmann's Virgo Cluster list, identified by his good position. ===== IC 3161 and IC 3162 are two stars, about 30 arcsec apart, which Schwassmann describes identically: "eF, vS, [perhaps] *". In a note attached to both, he goes on "I wonder if these are nebulous stars" (my free translation of his comment "in einer gemeinsamen Nebelhulle liegend"). His positions for both are very close to the modern positions, and the identities are sure. ===== IC 3162 is a star. See IC 3161. ===== IC 3163 may be the two stars that I've listed in the table, though they are pretty far from Schwassmann's position. Perhaps a defect is involved on the original plate, too. In any event, there are no galaxies nearby. Ames was the first to suggest the two stars, and Carlson picked this up for her 1940 ApJ list. ===== IC 3164 is a double star, seen, but not resolved, on the print of the original plate. Wolf's position angle is correct, and he notes that the object might be a double star, so that's what I've adopted. His position is good, too. ===== IC 3166 and IC 3180 are a pair found by Lewis Swift on 24 June 1897 during his several years observing from Echo Mountain north of Pasadena. Unfortunately, there is a large error in his positions for the nebulae as there is nothing within at least two degrees matching his descriptions: [IC 3166]: eeeF, S, 7 1/2 and 5 mag sts in field, p of 2. One of my faintest nebulae. [IC 3180]: vF, pL, R, 7 1/2 mag * south, f of 2. My own guess is that Swift rediscovered NGC 4284 and NGC 4290. His RA's would be fairly close (about 20 arcsec out), but his declinations would be 2 deg, 36 arcmin off. His relative brightnesses and sizes for the galaxies are correct, but I have trouble making the star field around the NGC galaxies match his description. There is a 6th magnitude star 14 arcmin south of NGC 4290; this may be his "7 1/2 mag * south" -- but where is that 5th magnitude star? I see no trace of it. Given that, I'm not even going to be putting the IC numbers in the position table with question marks. Similarly, Swift's nebulae could be NGC 3975 and NGC 3978. There, the Dec's are only 10.0 arcmin off, but the RA's are 24.5 minutes of time off. The two objects are closer together on the sky, though, and the problem of the star field remains. Here, there is a distinctive double star north of the galaxies, another of similar magnitude (about 10.5; I'm guessing here) west- southwest, and two brighter stars (9 and 7.5) east of the NGC objects. I also checked that one hour or ten degree errors were not involved. Nothing east or west, north or south, fits Swift's descriptions. I did not, however, check northeast, southeast, northwest, or southwest at these digit errors. In the end, I suspect the N4284/N4290 pair is what Swift actually saw, but ... ===== IC 3177 is almost certainly a defect on the Harvard plate on which Frost found it. The nominal position is in one of the overlap zones on the POSS1, so appears on eight different POSS1 plates -- not one shows a "F streak, ext 2.'5 at 45 deg" as Frost describes it. I searched for a similar object at reasonable RA and Dec offsets, but found nothing. So, even though I've not seen the original plate, I am quite certain that I3177 is a defect on it. Coincidentally, there is a defect on the DSS (but not on any of the POSS1 prints that I examined) just a few arcmin to the southwest of the nominal position. ===== IC 3178 is a star, probably with some extra plate grain mixed in with the image. It shows clearly on a contact positive print of the original plate, with IC 3179 (a galaxy) not very far to the southwest. The galaxy is sometimes called I3178, and a much fainter galaxy on a bit to the southwest is labeled I3179. However, there is no trace of this fainter galaxy on the print, while the brighter galaxy and the star are about equally bright and have similar sizes. ===== IC 3179. See IC 3178. ===== IC 3180. See IC 3166. ===== IC 3181 = NGC 4286. Here is another case where neither Wolf nor Dreyer caught a pretty obvious identity. The NGC position is less than an arcminute from Wolf's (copied correctly into the IC), so there is no doubt about the identity. ===== IC 3182 is just two stars, probably with a defect or random plate grain adding the appearance of nebulosity. Schwassmann's description reads "vF, S, li[ke] 2 F ** surr[ounded by] nebulosity, alpha delta :". There is a third star about 25 arcsec to the south that may have been involved with the image, too. ===== IC 3183 is a double star, perhaps connected to another star on the original plate by a defect or random grain noise? Schwassmann's position is close to the double, and the other star is less than an arcminute away. His description reads "vF, cS, perhaps 2 **, delta :". There is only one double in the area -- thus my lingering doubt about this. ===== IC 3190 is a star at Schwassmann's position. ===== IC 3191 is a star at Schwassmann's position. ===== IC 3197 is a star at Wolf's position. It is faintly seen on the print of the original plate. ===== IC 3211 = "NGC 4307A". There is nothing wrong with the IC identification -- the galaxy is just where Schwassmann puts it. The NGC number comes from RNGC and is based on Holmberg's list of double and multiple galaxies where it is number 380b. NGC 4307 is Holmberg 380a. This is why I don't like the suffixes. ===== IC 3213 is 40 arcsec north of Wolf's position. The identification is clinched by his mention of the "* 12 att np". The galaxy and the star, as well as several other galaxies in the area, are all visible on the print of Wolf's plate. Unfortunately, Wolf's marks are missing from this plate, but there is no doubt that he saw the galaxy and simply made a mistake in reducing its position. I do wonder, though, why he did not list some of the other galaxies; they are well seen. ===== IC 3214 is a star. It is at Wolf's position on the print of his plate, unmarked as are all of the objects on this plate. Wolfgang took a much fainter galaxy about an arcminute away; I did not see it on the print. ===== IC 3217. This is a star and a galaxy; the image is dominated by the star, but it still must have appeared slightly fuzzy to Wolf as he went over his plate. The unmarked image is on the print of his plate. ===== IC 3218 is described by Schwassmann as "Very faint, pretty large, extended, two nuclei, real??, RA and Dec uncertain." His position is also northeast of the galaxy, so the IC number pretty clearly includes the star 25 arcsec in that direction from the galaxy's center. ===== IC 3223 may be a defect on Schwassmann's plate. He says of it, "vF, pS, alpha :, delta :, am[ong] 3 vF sts." The three faint stars are clear on the sky today, and two of them have been taken as the IC object in various lists. Ames picked one (but did not give a position), while Wolfgang and I have two of them listed in the main table. The third is at 12 19 58.91, +09 45 58.0 for B1950.0 (my measurement on DSS). The problem, of course, with chosing any of these stars is that Schwassmann mentions them explicitly -- his IC object is not any of them. If his plate still exists (and it seems doubtful that it does), we could check the object there. ===== IC 3226 is probably just the star at Wolf's position. But there is another star about 20 arcsec to the southwest that may be involved with the object, too. Unfortunately, this is one of Wolf's objects for which his ink marks have been removed from his plate, so we can only verify that the stars are in fact present on it, not which one -- or both -- he meant to be his nebula. It's also curious that on the POSS1 version of DSS, the star at Wolf's position looks to be double. But on the POSS2 (red) DSS plate, the star is apparently single. Is there a small defect on the POSS1 red plate? ===== IC 3229 is often taken as the low surface brightness late-type galaxy (UGC 7448) 14 seconds of time following IC 3225 (= UGC 7441). However, Schwassmann's position and description make this unlikely. His position puts I3229 only 5 seconds of time following I3225, and he notes the object as being "on the edge of perceptibility." Furthermore, he found I3229 on just one plate, while I3225 appeared on two. All of this is enough to make me question the usual identification and suggest that Schwassmann's object is actually a defect or no more than random grain clumping. ===== IC 3232 is a star. I've not yet searched for it on the print of Wolf's plate, but his positions are good. ===== IC 3245 is a defect on the Harvard Bruce plate. Ames looked for the nebula on the same plate a quarter of a century after Frost found it, and found that it is, in fact, a defect. Frost himself suspected that, but put it in his list, anyway. I see no trace of the double star that Carlson credits to a Mt. Wilson observer (probably Hubble). ===== IC 3246. Though there is a galaxy at Schwassmann's position, it does not match his description ("eF, pL, li[ke a] li[ne] 145 deg, ?, alpha::, delta::". In particular, the galaxy is very small and round, so I suspect that there is a plate defect superposed on the original plate. ===== IC 3248, 3249, 3250, and 3251 are four of "about 18 pretty definite nebulae, [forming a] long chain from south to north" on the plate which Wolf examined to find the nebulae in his fourth list. Of these four nebulae, only one (IC 3249) is a galaxy, and the other "nebulae" in the chain are either stars or defects. There is a defect involved with IC 3249, and all of the several fainter objects around it are far too faint to show up on Wolf's plate. This is definitely a case where Wolf pushed his plate limit too hard. ===== IC 3249. See IC 3248. ===== IC 3250 is a star. See IC 3248 for more. ===== IC 3251 is a star. See IC 3248 for more. ===== IC 3252 is a double star. Like most of the objects in Wolf's fourth list, it is not marked on the print of his plate that I have. And I have not checked the print for this, either. However, the position alone is enough to clearly identify Wolf's object. ===== IC 3254 = NGC 4336 is the most likely explanation for the IC number. However, there is some doubt about this. Here is the story. The object was discovered by Royal Frost on an Arequipa Bruce 24-inch plate (number 6719, taken the night of 9 May 1904), and is included in his list in HA60 as number 884. He gives a position of 12 18.5 +20 01 (1900) which is northeast of NGC 4336 by about 2.5 arcmin. It falls within an arcminute of a 14th magnitude star. However, Frost does not mention NGC 4336 anywhere in the section of the paper devoted to his nebulae. In this respect, N4336 is included in the large majority of NGC objects that were just where he expected to find them. In particular, he does not include N4336 in his list of missing NGC objects. Also, his description is "Plan[etary], R, B, d 0.4'." Because the inner bright part of N4336 is over an arcmin across and is clearly not round -- though it is clearly bright! -- Frost's description does not fit the galaxy very well. So, it is possible that he was actually describing the star, perhaps with a defect superposed (this could, of course, be checked on the Harvard plate which surely still exists in their collection). On the other hand, Adelaide Ames -- in her Virgo Cluster catalogue in HA 88, No. 1 -- adopted the identity and gives it explicitly in her Table 1. For this object, she used the same plate that Frost searched 30 years before (Arequipa Bruce plate no. 6719), and she found no other objects within at least 10 arcmin of her position for N4336 (she adopted the NGC position which is a bit off). Since Ames was a meticulous astronomer (Shapley greatly missed her careful work after her tragically early death by drowning), I'm giving a considerable amount of weight to her decision to make the two objects identical. CGCG and MCG come to the same conclusion, though using only the data presented in the NGC and IC; they almost certainly did not have access to the original plate on which the IC object was found. So, I've accepted the identity -- but have also added the position of the star to the position list as a possible candidate for the IC object. ===== IC 3256 = NGC 4342, IC 3259, IC 3260 = NGC 4341, and IC 3267. Though the IC identifications in this group of five galaxies are not ambiguous, the NGC identifications have been. See the discussion under NGC 4341, and in RC3 (the Introduction, page 60; and Appendix 6, page 551). ===== IC 3257 is one of Bigourdan's "fausse images." He has one observation of it in April of 1895, calling it a "Trace of nebulosity nearly completely unseeable." In May of 1907, he said, "I can once in a while see this eF object," but made no measurement of it. There is nothing in his position. Malcolm pointed out that the declination of Bigourdan's comparison star is incorrect in the big table of observations. Nevertheless, the position in the IC is reduced correctly, so this is just a typo. Malcolm also points out that the object at Bigourdan's position seen on the red POSS1 -- thus also on DSS -- is a defect. It is not on the blue POSS1, nor is it on the POSS2. ===== IC 3259. See NGC 4341. ===== IC 3260 = NGC 4341, which see. ===== IC 3261 is probably one of two galaxies near Frost's position. I favor the smaller but brighter one because it matches his description -- "Sp., F * at center, d 1', doubtful" -- better than the larger, low-surface-brightness galaxy to the northeast. In particular, the "F * at center" is missing in the larger galaxy. But that object is closer to Frost's diameter of 1 arcmin. So, we're stuck until we can examine his plate. ===== IC 3265 is a star clearly identified by Schwassmann's good position from a 6-inch Heidelburg plate. However, CGCG put the number on NGC 4353, and we've had trouble with it ever since. Well, it's sorted out now. Actually, Adelaide Ames sorted it out in 1930, and we're just now catching up to her. ===== IC 3266 = NGC 4353, which see. There is no problem with the IC identification -- at least there wasn't until CGCG put it, along with IC 3265 and NGC 4353 on the galaxy. See the other numbers for the short story. ===== IC 3267. See NGC 4341. ===== IC 3272. Wolf's declination is actually that of his "* 13 att n", but the identity of his galaxy is clear. It is also clearly seen on the print of his plate, though as with all the other nebulae he found on this plate, it is now not marked. ===== IC 3273 = NGC 4356. Here is another case where Schwassmann missed the NGC number on one of the nebulae that he measured on a Heidelberg plate. Both his position and WH's are good, so Dreyer had an opportunity to equate them, too. The identity was first suggested by Adelaide Ames in her 1930 Virgo Cluster catalogue. ===== IC 3279 is two stars, oriented very nearly east-west. Schwassmann describes his object as "pF or pB, S, perhaps 2 stars, p 11.8, f 10.8". While his magnitudes are estimates, the eastern star is indeed the brighter and thus secures the identification. ===== IC 3281 may well be a defect. There is nothing at either of Schwassmann's positions (only a few arcsec apart). Even though he has two measurements of the object, they are probably just that: two measurements on a single plate, referred to comparison stars in different zones across the plate. The object is unlikely to be the faint star that Wolfgang chose if only because it is almost two arcmin away from the nominal position. Schwassmann's descriptions make it unlikely in any case: "pB, cS, R, N, li[ke] *" and "cB, pS, R, li * 10-9, d = 25 [arcsec]". This would be an obvious object, and there is just nothing in the area like this. It could also be another Virgo Cluster galaxy with a measurement or reduction error. I think this is less likely as both of Schwassmann's positions are within his usual errors of being identical -- but they ARE different. I do not see any galaxy that is likely to be Schwassmann's object that is not already in his list. In particular, NGC 4365 is exactly 30 arcmin south, and NGC 4470 is 5m 10s east and 10 arcsec north. But he already lists both, so I do not think that I3281 is either one of them. So, another lost nebula. ===== IC 3282 is a star. Wolf's position is good, and I have no doubt that the object will show up on the print of his plate. ===== IC 3285 is a star at Wolf's position. ===== IC 3295 is a plate defect on Wolf's original plate. It actually covers the star that Wolfgang chose as the IC object, but is centered enough off it to make it clearly a defect. It is also surrounded by an annulus darker than the sky background in the area. It is clearly seen on the print of the original plate. ===== IC 3297 is a star. It is clearly seen on the print of Wolf's plate, though it is unmarked, as are all the nebulae found by Wolf on this plate. ===== IC 3301 = IC 3307. The identity was first noticed by Ames who presumeably checked it on the Bruce plates, numbers A6718 and A6720, on which Frost found the nebula. Even without her note in HA 88-1, we would be quite sure of the identity as the galaxy sits between Frost's two positions, and is the only one in the area bright enough to have been picked up by him. ===== IC 3310 is a star superposed on the northwestern arm of NGC 4396. However, Bigourdan has an incorrect position for his comparison star listed in his big table. This led to an incorrect RA in his CR list and the IC. When the position is corrected (his approximate offsets of his comparison star from NGC 4379 ARE correct), the object turns out to be the star on the arm of NGC 4396. He has four observations of the star which pin it down precisely. Curiously, Bigourdan measured NGC 4396 itself on the same night using the same comparison star about two arcminutes northeast of the center of the galaxy. Yet he somehow confused the field so that IC 3310 was taken to be another star nearly 45 seconds of time away by both the Harvard and Mt. Wilson observers. ===== IC 3318 is a star at Schwassmann's position. ===== IC 3319 is perhaps = NGC 4390 = IC 3320. Found by Schwassmann on his 6-inch plate of the Virgo Cluster area, this does not exist -- or is identical with IC 3320 = NGC 4390. Though there is a faint star less than an arcminute west-southwest of Schwassmann's position, this does not match his description which is identical to that for N4390 (which Schwassmann did not name as the NGC object, by the way). Is it possible that he made an error in his measurement reductions for the IC objects? They occur in different declination zones in his list, so this is a possibility. ===== IC 3320 = NGC 4390, which see. Also see IC 3319. ===== IC 3323 is a star superposed on the southwestern side of NGC 4393 (the CGCG has it equal to the galaxy along with IC 3329, which see, but this is wrong). Wolf's position is very close to the star, and though his markings have been removed from his plate, the object is there on the print of the plate that I examined. ===== IC 3329 is a knot in NGC 4393, east of the nucleus. It is visible on the print of Wolf's plate that I examined, but his marks have been scrubbed off the plate. Neverthless, the identification is secure. CGCG has this (along with I3323) equal to N4393 itself, but this is wrong. ===== IC 3333 is a star just north of NGC 4402. Schwassmann's position is very good, and his description "vF, vS, perhaps * 13.8" is appropriate. ===== IC 3335. There is another somewhat brighter galaxy about an arcmin to the north-northwest that has sometimes been taken as IC 3335. However, not only is Wolf's position precisely on the fainter object, the brighter one appears stellar on the contact print of Wolf's original plate. ===== IC 3339 = NGC 4411. Here is another obvious identity that might have come about because neither Dreyer nor Schwassmann checked the NGC carefully (there are several of these in Schwassmann's list -- see e.g. IC 3098 and IC 3113 -- and I expect we'll turn up a few more before we're done). However, in this case, Dreyer was distracted by Bigourdan's discovery of a second object nearby. Dreyer's Note in IC2 tells what happened next: "[NGC] 4411 I assume that B. 298, 12h 19m 40s, 80d 21m, vF, L, 2.5 arcmin is identical with this." (See NGC 4411 for more on Bigourdan 298.) I'm actually puzzled by this because the NGC and IC positions for N4411 and I3339 are almost identical, differing by only one second of time and 0.2 arcmin. Why should Dreyer choose another object 17 seconds of time away when he had an obvious candidate in the same place? Just the distraction, I presume. Or, as I've suggested elsewhere in these notes, Dreyer was getting tired of cataloguing nebulae, and was not paying as much attention as he might have earlier in his career. As far as I can tell, Adelaide Ames was the first to suggest this identity. In any case, Schwassmann's description -- "* 11, north-following [is] surrounded by much nebulosity" -- is appropriate, and makes clear that he was indeed seeing the galaxy. ===== IC 3343 is probably the star that I've included in the position table. It is just east of NGC 4411 = IC 3339 (which see). There are two other stars that might have been involved, though, as might the eastern reaches of NGC 4411 itself. Schwassmann's position is not particularly close to any of the three stars (I've taken the nearest), and his object could well be a blend of any two or even all of them. His description "eF, vS, ??, alpha delta ::" is not too helpful, either. ===== IC 3350. There is a pretty bright star at Schwassmann's position (matching his description "perhaps * 10-11, sp surr m n"), but there must have been a defect involved, too. How else can we explain his comment "southwest [it is] surrounded by m[uch] n[ebulosity]" that he adds? There is nothing on the DSS aside from the star, so I am pretty confident about the defect. ===== IC 3351 is a star. It is clearly seen on the print of Wolf's original plate. Wolfgang took a brighter star to the southwest as the IC object, but that is clearly stellar on the plate. ===== IC 3352 may be a defect on Schwassmann's plate. There is nothing at his position. NGC 4411B is almost straight north -- but by 7 arcmin, 37 arcsec. Unless this is a unit (or ten, or 100) in Schwassmann's measuring system, I don't think Bigourdan's object is the one Schwassmann measured. Similarly, there is a small, faint galaxy 6.0 sec west, and 1 arcmin 5 arcsec south. I think this has a better chance of being the correct object, but I'm still not betting on it. We obviously need to check the plate, if it still exists (which, we are told, does not). ===== IC 3353. Wolf's RA is 3 seconds of time too small. But there is nothing in that place and the galaxy is clearly seen on the print of the original plate. ===== IC 3354 is a star at Schwassmann's position. ===== IC 3360 is a star at Wolf's position. I've confirmed the object on the print of the original plate. ===== IC 3361. While there is nothing at Frost's position, there are two obvious candidates for this number. Unfortunately, neither galaxy is the outstanding choice. One, a large low-surface-brightness dwarf spiral five seconds west and an arcmin north, matches Adelaide Ames's diameter and magnitudes in her 1930 Virgo Cluster catalogue (she worked from the same plates that Frost used 30 years earlier). But was this really the galaxy that she and Frost measured? Five seconds east at the nominal declination is a much smaller galaxy -- but it has a much higher surface brightness so might be picked up more easily in spite of its size. In the end, I slightly favor the larger galaxy, but we'll have to take a look at the Harvard plate to be sure. ===== IC 3366 is a faint galaxy just south of NGC 4424. Schwassmann made some error in his measurement or reduction of it and a nearby star -- both are just 4.0 seconds west and 15 arcsec south of his positions. His description of the galaxy is appropriate: "vF, vS, nf surr m n". The last bit "translates" as something like "surrounded by much nebulosity north-following." (He uses the same phrase to describe IC 3339 = NGC 4411, which see, where the description is a bit more apt because of the star superposed on the galaxy.) Whatever happened, I am confident of the identification because of the note about the "nebulosity" to the northeast. This is clearly a reference to NGC 4424. ===== IC 3372 is a star with a superposed defect at Wolf's position. It shows clearly on the print of the original plate. There is a fainter merged double star to the northeast that is sometimes incorrectly called I3372; this is just visible on the print, but is little more than random grain clumping. ===== IC 3375 is a star. It is close to Wolf's measured position and is clearly seen on the print of the original plate. Wolfgang mistakenly chose a nearby galaxy as the IC object. This, too, appears on the print of the original plate, but is smaller and fainter than the star Wolf measured. It appears stellar on the print, so Wolf must have skipped over it, thinking it a star. ===== IC 3399 is a star at Wolf's position. I've not yet looked for it on the print of the original plate, but the identification is nevertheless secure. ===== IC 3400 is a fairly bright star at Schwassmann's position. His description "cB, cS, li[ke] * 10" is appropriate. The identity was first suggested by Adelaide Ames and picked up by the Mt. Wilson observers for Dorothy Carlson's list, too. ===== IC 3402 is a nice edgewise galaxy just about an arcmin south-southeast of a pretty bright star. Wolf's position is about 15 arcsec too far north (along the major axis of the galaxy, still well within its image), but otherwise his data for the galaxy is appropriate. Even though this is one of the northern- most galaxies on his plate, well into the vignetted area of the plate, it is still clearly seen on the print of the original plate. ===== IC 3404 is probably a defect on Schwassmann's original plate. There is no trace of a "cB, cS, li * 10-11, surrounded by much nebulosity" galaxy in the area. There are also no galaxies at reasonable digit errors from Schwassmann's published position. The only possibility is NGC 4464, but that is not exactly one degree north, and Schwassmann has an entry for it, in any case. ===== IC 3408 is a pretty bright star (10 magnitude) at Schwassmann's position. His description ("neb or *, B, li * 9.2-9.5") is appropriate. ===== IC 3415 is a star found by Max Wolf on one of the plates he took early in the 20th century at Heidelberg. The position he measured is good. ===== IC 3417 is a star about 2.3 arcmin north of NGC 4470. It is often incorrectly equated with the galaxy (Adelaide Ames was apparently the first to do this), but Schwassmann's position is exactly on the star. In addition, his description "eF, vS, ?*" fits perfectly. Finally, Schwassmann has two other entries in his list for NGC 4470, both correctly identified as the NGC object. ===== IC 3420 is a star north and just a bit west of NGC 4473. Schwassmann's position is off by a few arcsec, perhaps affected by the corona of the galaxy. ===== IC 3423 is a star close to Schwassmann's position a few arcminutes west- northwest of NGC 4477. His measured position is within 5-6 arcsec of the star, yet both the Harvard and Mt. Wilson observers listed I3423 as "not found." Dreyer copied the position correctly into IC2. ===== IC 3426 is a star about 2 arcmin south of NGC 4477. Schwassmann's position is about 10 arcsec north of the star, perhaps confused a bit by the corona of the galaxy. ===== IC 3427 = NGC 4482. William Herschel's RA is 30 seconds of time too large. Dreyer has a note about this in WH's Collected Papers. This is not an isolated error, as Dreyer adds "... same sweep as the last three, 174." The "last three" are the previous third class objects seen in the sweep, all with RA's too large by up to a minute of time, and referring to a general note under H II 64 = NGC 4352. Apparently most of the objects in the sweep are affected by the same error. Curiously, even though both Bigourdan and Dreyer noted WH's position error, Dreyer did not make the connection with IC 3427. That was left for Ames and Carlson. ===== IC 3428 is a star. Wolf's position is good, though his image may include the very galaxy or double star about 20 arcsec to the north. ===== IC 3438 = NGC 4492. Schwassmann has two entries for the galaxy in his table, but from different plates. The descriptions are comparable, and the positions are about 10 arcsec different, but still within the boundaries of the image of the galaxy. The identity was first suggested by Adelaide Ames in her Virgo Cluster list of the 1930's. It was picked up by the de Vaucouleurs for RC1, and also by Zwicky, Herzog, and Wild for CGCG. Wolfgang adopted the identity for his list, and Bob Erdmann also noticed the identity. He alerted me, and I have finally got the two galaxies equated here. Sometimes, it takes more than a village. ===== IC 3444 is a double star, easily seen on the print of Wolf's original plate. ===== IC 3450. Wolf's position is 44 arcsec north of the true position. The galaxy's image is on the print of his plate at the correct position, so this suggests that he has made a measurement or reduction error. His description is appropriate for the object, and there are no others nearby that match, so there is little reason not to accept the identification. ===== IC 3452 = NGC 4497. There is no doubt about this identity. As with several other of Schwassmann's objects, the only doubt is why both he and Dreyer missed the identity with the NGC object. Both the IC and NGC positions are near the modern position for the galaxy. Furthermore, Schwassmann has two accordant measurements and descriptions for the galaxy. The only difference with the image on the DSS is the position angle: Schwassmann gives 100 degrees, while the outer isophotes of the galaxy are closer to 70 degrees. However, the bright inner part is closer to Schwassmann's PA, suggesting that his plates showed only this piece of the galaxy. It's also possible that he got the quadrant wrong, and that he meant to write 80 degrees instead of 100. ===== IC 3456. There is nothing on either the DSS nor on the print of the original plate at Wolf's position. There is not even a defect on the original plate. So, I suspect a measuring or reduction error on Wolf's part. Unfortunately, Wolf's marks have been almost completely removed from the plate. So, we have almost no way to track down the object that Wolf saw. This is especially true since he was working so close to the plate limit -- his object could be one of literally hundreds of faint stars or defects on his plate. ===== IC 3463 is a wide double star, or perhaps just the northern of the two. Schwassmann's position is closer to the northern, but his description includes the position angle (40 deg) appropriate to both stars. I've opted to call the double IC 3463, but have included the two stars separately as well. ===== IC 3464 is a star with a defect superposed on the print of the original plate (the defect is probably on the original plate as well). The image is elongated, so it is not surprising that Wolf mistook it for a faint nebula. ===== IC 3477 is a star. It's image is clearly seen on the print of Wolf's original plate. Wolf's declination is a bit off, but there is nothing exactly at his position, so I am pretty sure that this is the correct object. ===== IC 3480 is a double star. Not only is Wolf's position exactly on the stars, but his position angle for them is correct, too. Since there is no other object near this that meets the description, the identification is firm. Note that the MOL identification of this with IC 3490 is in error. I3490 is 16 deg south in the Virgo Cluster. ===== IC 3485 is another star, identified by Schwassmann's good position measured on his plate of the Virgo Cluster. ===== IC 3490. See IC 3480. ===== IC 3493 is probably a star. The situation is odd: Schwassmann has accurate positions for IC 3487 just west of I3493, and for a star just east. These agree to within a few arcsec of the modern positions. However, for I3493 itself, Schwassmann's position is 2 seconds of time east, and 12 arcsec south of the star that he perhaps measured. Is there a defect superposed that pulled his position off? We may never know, as his plates are reported to be missing from the plate vaults in Heidelberg. ===== IC 3495 is a blended double star at Wolf's position. My earlier idea, unfortunately copied into MOL, that this is KUG 1231+270 a couple of arcmin southeast is incorrect. Forgive me; I was young and naive. ===== IC 3496 is a star, blended with a defect. Though Wolf's position is well north of the position of the star, there is nothing exactly at his position on the print of the original plate. Furthermore, the star image is elongated on the print of his plate, and is quite eye-catching compared with the simple stars in the field. My earlier identification of this with IC 3498 (copied into MOL) is wrong; Wolf's positions are very good, and his description of I3498 makes it unmistakable. ===== IC 3497 is a star. It is clearly seen on the print of the original plate. ===== IC 3498 is not a star as I had surmised earlier. Wolf's position and description unequivocally point at the correct galaxy, a highly inclined (early-type?) spiral. The image is easily seen on the print of the original plate. Unfortunately, MOL copied my earlier mistaken identity. Sorry about that. (Also see IC 3496.) ===== IC 3502. Wolf's position is significantly south of the position of the galaxy. There is a faint star just south-following the galaxy which is blended into the galaxy image on the original Heidelberg plate; only a single image is visible on the contact print of this plate. This pulled the center of the image south, and also accounts for Wolf's classification of "irregular." ===== IC 3503 is a star. It was the last object found by Javelle on 13 June 1896, a relatively productive night for him -- he found six galaxies as well as this star. Given its faintness, I was a bit skeptical about the identification, first suggested by Wolfgang. But there is no galaxy nearby that Javelle could have seen, nor are there any at sign-error offsets from his comparison star. Nor are there any other star galaxy pairs in the area that have the correct offsets and brightnesses. Finally, Javelle has no significant systematic error in his measurements for the night that might lead to a galaxy. So, by a process of elimination, we come back to the star. Reducing Javelle's measurements with respect to the AC 2000.2 position for his comparison star, his position for the faint star is just 7 arcseconds off the position I measured on DSS. This is just about Javelle's standard deviation, his "one- sigma error", so I am taking the star as his object with no further complaint. ===== IC 3504 is a star. Schwassmann notes "near * 10". That brighter star is 1.0 arcmin north. ===== IC 3511, 3512, and 3513 are stars involved with defects on Wolf's plate. All are seen as faint "nebulae" on the print of that plate. On the DSS and POSS1, IC 3511 has a very faint galaxy just to the west of the star, but this is not visible on the print of the original plate. ===== IC 3512. See IC 3511. ===== IC 3513. See IC 3511. ===== IC 3514. This is a double star. The position and position angle given by Wolf are exact, and there is no other object nearby that he could have mistaken for a nebula. The object is also clearly seen on the print of Wolf's original plate. ===== IC 3524 is a star with a fainter star about 30 arcsec to the southwest. Schwassmann's position is good. ===== IC 3526 is a double star. It is clearly seen, though only as a single object, on the print of the original plate. ===== IC 3527 is also a double star. And like IC 3526, it is clearly seen, though only as a single object, on the print of the original plate. ===== IC 3529 is a star. It is clearly seen on the print of the original plate. ===== IC 3532 is a star blended with the image of a fainter object just west. I think that the western object is a galaxy, but cannot tell for sure on DSS. On the print of Wolf's original plate, this appears as a single object. ===== IC 3534. Though Frost's RA is 22 seconds of time off, more than twice the usual error (between 1 and 2 arcmin) that we usually associate with his positions, the identification is pretty secure. There are no galaxies closer to the nominal position that might be Frost's object, and this one matches his description well enough. ===== IC 3535 is a star. It is clearly seen on the print of the original plate. ===== IC 3537 is another star in Schwassmann's list identified by his good position. There are two other stars flanking it to the northwest (brighter) and to the south (fainter), but Schwassmann does not mention either of these. ===== IC 3538 is a star at Wolf's position. His description ("S, eF") is appropriate, too. ===== IC 3539 is a star. It is clearly seen on the print of the original plate. ===== IC 3541 is a star very close to Wolf's position. Wolfgang took the fainter star just southeast in his first sweep through the IC. This is not on the print of Wolf's plate while the brighter star is. ===== IC 3544 is a double star exactly at Schwassmann's position, and matches his description pretty well: "cF, vS or S, ph * 12.5" ("ph" = perhaps). His magnitude estimates tend to be too bright by 2 or 3 magnitudes -- the double is more like 15. ===== IC 3545 = NGC 4555, which see. ===== IC 3547 is a star, probably with a plate defect superposed. The defect is faint enough that it does not show well on the print of the original plate, though the star is easily seen. Wolf's marks are no longer on this plate, but his description reads "little extended, [PA =] 70 [degrees]." His position is within 5 arcsec of the star, so there is little doubt about at least that part of the image. ===== IC 3549 is a star. As with I3547, Wolf's discovery plate has been wiped clean of his marks, but the position points very closely to the star -- which is easily seen on the plate -- and Wolf's description (vF, vS) is appropriate for the object. ===== IC 3550 is an HII region in NGC 4559, easily seen on the print of Wolf's original plate. See IC 3554. ===== IC 3551 is an HII region in NGC 4559, easily seen on the print of Wolf's original plate. See IC 3554. ===== IC 3552 is a compact HII region in, or a foreground star superposed on, NGC 4559. In either case, it is stellar or nearly so on DSS, and is close to stellar on the print of the original plate. See IC 3554. ===== IC 3553 is a star at Wolf's position. Though no longer marked on the discovery plate, Wolf's description (vF, vS) is appropriate, too. ===== IC 3554 has a very good position in Wolf's fourth list. Thus, it can be easily identified with a star superposed on NGC 4559. I3552 is either a star or a compact HII region. The other objects that Wolf saw in the arms of N4559 (I3550, I3551, I3555, I3563, and I3564) are indeed HII regions and/or star clouds in that galaxy. They all show up on the print of his original plate. ===== IC 3555 is an HII region in NGC 4559, easily seen on the print of Wolf's original plate. See IC 3554. ===== IC 3556. Even though Wolf's photographic position in his 4th Konigstuhl Nebel-List is exact, CGCG, MCG, UGC, and PGC have all ignored the number in favor of NGC 4563, NGC 4558, NGC "4536" (typo for 4563), and NGC 4558, respectively. Wolf identified the NGC galaxies correctly, too, giving good positions for them, so we can be certain that IC 3556 is a "nova." See NGC 4558 and NGC 4563 for further discussion. ===== IC 3557 is a double (at least) galaxy in a compact group, which is, in turn, in a cluster. There are at least 4 companions nearby -- and on DSS, a defect as well. The defect, fortunately, is in an empty bit of sky just northeast of the IC object. ===== IC 3558 is noted as a double nebula by Frost, but the northern object may be a superposed star, not a second galaxy. ===== IC 3563 is an HII region in NGC 4559, easily seen on the print of Wolf's original plate. There is a foreground star just south that is probably included in Wolf's image, though that image is a single blob also including IC 3564 (which see). Wolf's original plate must be clearer in this area as he was able to make two objects out of the single blob on the contact print. Also see IC 3554 for a bit more on the objects around NGC 4559. ===== IC 3564 is a star cloud in the outer arms of NGC 4559. Though it is clearly visible on the print of Wolf's original plate, it is completely blended with the image of IC 3563 (which see) and a foreground star (which I mistakenly took to be I3564 when I first went over this area in the early 70s at Texas). See IC 3554. ===== IC 3566 is probably a defect -- but just possibly may be a comet. Found by Frost on Harvard plate A6720 (10 May 1904), he described it as "Com., head R, tail 1.0' long at 110 deg." Adelaide Ames, in her 1930 catalogue of the Virgo Cluster, says simply "A comet" in her footnote to a list of NGC and IC objects which she could not find. She examined the same plate that Frost used. Brian Skiff and Larry Wasserman at Lowell Observatory have run Frost's position (12 31.3 +11 43; 1900) through a comet identification program, and came up empty-handed. The nearest known comet was 10P/Tempel 2, but it was more than 15 deg away (at 13 36 11, +12 45.2) on 10 May. On Brian Skiff's advice, I also asked Brian Marsden to run his software to check his comet catalogue. He wrote back, "I don't see any known comet that IC 3566 could have been." So, it is almost certainly a defect on the old Harvard plate. ===== IC 3569 = NGC 4561, which see. ===== IC 3570 is a star, seen on the print of Wolf's original plate. ===== IC 3572 is a double star close to Schwassmann's position. ===== IC 3577 is a defect on Schwassmann's plate. We can be sure of this because there is nothing exactly at his position. But just to the northeast is a "* 12.8" which Schwassmann calls "* 207a" in his list (IC 3577 is itself number 207 of his list). Schwassmann's description of the IC object reads "vF, pS or cS, dif, cont[ains] * 207a". There is another fainter star on star on to the northeast that may also have been involved in Schwassmann's "nebulosity". ===== IC 3579 is a star just a few arcsec from Wolf's position. I've not yet looked at it on the print of the original plate, but I have little doubt about the identification. ===== IC 3582 has been misidentified by nearly everyone as the brighter galaxy southwest of the real I3582. Wolf's position is exact for his object, and it appears as a nearly stellar object on the print of his original plate. The brighter galaxy to the southwest (UGC 07778) also appears on the print, and it too appears to be stellar. I suspect that this is why Wolf skipped over it. ===== IC 3584 is a star, clearly identified by Schwassmann's good position. ===== IC 3588 = NGC 4571, which see. ===== IC 3589 is a star just north-preceding IC 3591. Schwassmann has the following data (equinox 1900.0) for these two objects: Working Running Number Number On Plates Object Sn (Sn) Zone RA Dec Desc I3589 29 7 Ia2 12 31 56.23 +07 29 13.2 vF, pS, R, li * I3591 30 6 Ia2 12 31 57.99 +07 28 35.0 F, pS 47 II3 12 31 58.24 +07 28 36.3 F, cS, nr * 14, alpha, delta: Note that IC 3589 was picked up in only one zone of the two that Schwassmann searched across this area. If we adopt 12 31 58.07 +07 28 35.4 for IC 3591 (half weight for the 2nd position which is noted uncertain) then the differential position with respect to I3589 is 27.4 arcsec in RA and -37.8 arcsec in Dec. Measured on the Sandage-Binggeli photo in their Paper III (Plate 52, p. 1095, AJ xx, 198x), the difference in position between the galaxy and the brighter star to the upper right is 26 arcsec in RA and -34 arcsec in Dec. Within the errors of my measurements (a few arcsec), the offsets agree, so IC 3589 is certainly the star. ===== IC 3591. See IC 3589. ===== IC 3594 is a star with a defect superposed. Both are very faint, but visible, on the print of Wolf's original plate. ===== IC 3596 must be a defect. Wolf's position is just north-northeast of a wide double star, and his description reads, "Wings [curving arms], near a double star." There is nothing at all on the POSS1 in this place, and Wolf's mention of the double star near the "nebula" rules it out as his object, too. Since I wrote that, I've examined the print of Wolf's original plate, and can in fact see the defect north-northeast of the double star. ===== IC 3601 is a perfectly good galaxy, the brightest in a relatively compact group, about 1.5 arcmin north of Frost's position. Nevertheless, Ames has this to say about the IC number: "A defect on the plate where it was originally found by Frost." I suppose this is a possibility -- we will need to examine the plate to be sure. But the galaxy is similar to dozens of others in the area of the Virgo Cluster that Frost (and Ames) found. So, until we know for sure that it is in fact a defect, I'm going to keep the IC number on the galaxy. ===== IC 3602. There are two clear candidates for this object -- a relatively larger, lower surface brightness galaxy preceding Frost's position; and a smaller, more compact object that is the brightest in a quadruple interacting system (a triplet of fainter galaxies precedes the brighter object by about half an arcmin). Most of the catalogues have taken the preceding low surface brightness galaxy as the IC object. However, it does not match Frost's description which reads "F, R, lbM, dia = 0.1 arcmin." The preceding object is actually closer to half an arcmin across. So, while Frost does indeed have objects like it in his list, I don't believe that it was this galaxy that he picked up. Nevertheless, I'm out-voted on this, so have to put a colon on the IC number for the following, more compact galaxy. And I have to include the preceding galaxy -- but I do so with a question mark firmly attached to the number. ===== IC 3606 is a compact galaxy, not a star as we had it for some time. Apologies to all. ===== IC 3607. Though called a star in Carlson's 1940 list, this is clearly a galaxy on the DSS. Ames also has it as a galaxy in her 1930 Virgo Cluster catalogue. ===== IC 3609 is a pretty compact galaxy. It was misidentified in CGCG, and that incorrect label has been carried along into UZC. But other lists (VCC, VPC, and Wolfgang's) have the right galaxy. ===== IC 3610 appears as a very faint, irregular, linear image on the print of Wolf's original plate. It turns out to be a line of three faint galaxies plus a star. Wolf's position is just to the east of the galaxies, but is good enough to unambiguously identify the objects. ===== IC 3612 = IC 3616. Royal Frost found these "two" nebulae on two different overlapping Harvard plates. His two positions are only a tenth of a minute of time apart, and his descriptions are similar. Since there is no other galaxy nearby which is bright enough to be picked up on the plates, the identity is virtually certain. ===== IC 3613 is a compact galaxy about 1.5 arcmin north of Frost's position. Glen Deen took another fainter galaxy west of Frost's position, but this has a much lower mean surface brightness -- I doubt that it shows up on the Harvard plate. ===== IC 3614 is a star and a galaxy forming a single elongated image on the print of Wolf's original plate. There is another galaxy nearby that might be mistaken as IC 3614, but it is fainter and is just barely visible on the print. ===== IC 3616 = IC 3612, which see. ===== IC 3619 is a double star, unresolved on the print of Wolf's original plate. ===== IC 3628 is a star, verified on the print of the plate from which Wolf assembled his fourth list of new nebulae. This is one of the plates from which Wolf's discovery markings have been erased, but the image of the star can be clearly seen at Wolf's published position. ===== IC 3630 is a star. It's image is on the print of Wolf's original plate. ===== IC 3636 is a double star (or perhaps a triple; the fainter star looks like a blended double star itself on the DSS). It was found on a plate taken by Max Wolf with the 16-inch Bruce refractor at Heidelberg on 27 January 1904. He published it and 197 other objects as new nebulae in 1905, and Dreyer incorporated most of them into the second IC. Wolf also measured positions for six NGC and IC1 objects on the plate. As with most of the other plates in this series, we have been fortunate to be able to compare prints of them, kindly made for us by Dr. G. Klare at Heidelberg, with the POSS1 and with the DSS. This plate, and two of the four others, still carry Wolf's original ink marks identifying the objects which he catalogued. This has made possible the positive identification of almost all of Wolf's objects on this plate which were included in the IC. By the time Wolf examined this plate, he had clearly refined his techniques considerably over his first paper of new "nebulae," where most of the objects are in fact faint stars. Here, only 55 stars or defects are included as nebulae -- still a relatively high percentage, but not too bad considering that Wolf was working with images near the limit of the plate (about 18th magnitude). ===== IC 3640. See IC 3641. ===== IC 3641 is about 30 arcsec southeast of IC 3640. Wolf has only one entry for the two objects in his 4th list of new nebulae found on a Heidelberg plate; I3641 is actually mentioned in the note to I3640. Wolf has the direction wrong in the note -- instead of "np," it should read "sf." Both objects are visible on the print of the original plate, though I3641 is almost indistinguishable from plate grain. ===== IC 3644. See IC 3645. ===== IC 3645 is a star. It is on the print of the original Heidelberg plate, but Wolf's marks have been scrubbed off this plate. Thus, we have only his good position to lead us to the star. I3644 and I3646 are just to the south, and the pair I3640/I3641 (which see) just to the west. ===== IC 3646. See IC 3645. ===== IC 3648 is a star, as with many others, accurately identified by Schwassmann's good position. ===== IC 3650 is a double star. Wolf's position is biased toward the brighter, northwestern star, though its image is blended with that of the southeastern star. ===== IC 3657. My first look at the print of the original plate suggested that this is nothing more than a defect. However, as Wolfgang and Malcolm have found, there is in fact a faint star just south of Wolf's position. A second look shows that the image of the star was indeed faintly recorded on Wolf's plate. I suspect that the original plate would show it more clearly. See IC 3636 for more about this discovery plate. ===== IC 3660 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3663 is a pretty low surface brightness galaxy which Frost found on the Bruce plate taken at Arequipa. There is a brighter compact galaxy to the south-southeast which has been mistaken for the IC object, but it probably appeared stellar on the Bruce plate. Whatever happened, Frost skipped right over it. ===== IC 3664 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3666 is a star. Schwassmann has the description as "eF, vS, ?, [alpha]:, [delta]:". The lonely question mark is interesting -- Dreyer even copied it verbatim into the second IC. It, and the colons on the position symbols, show that Schwassmann was not particularly confident about this object. However, the star is there on the DSS, so Schwassmann's plate did record something at his position. There may also have been a defect or a bit of random grain noise that lent a bit of fuzziness to the image, too. ===== IC 3667 = NGC 4618, and IC 3675 = NGC 4625. I have no idea how these identities came about, aside from a coincidence of oversight by both Max Wolf (in whose 5th Konigstuhl list the IC objects first appear) and Dreyer. The NGC and IC positions are vitually identical in both cases, and Wolf's descriptions -- liberally sprinkled with exclamation points -- leave no doubt as to which objects he saw on his plate (the correct objects are clearly marked on the print of the plate that I've compared to POSS1). Perhaps both astronomers were becoming bored with long lists of faint nebulae by 1904 and just didn't do the careful checking needed. Whatever the case, there is no doubting the identities. The second has been noted in several galaxy catalogues (RC1, MCG, etc.), but the first has been overlooked. I suspect that the feeling, on seeing an IC number attached to an 11th magnitude galaxy, was one of disbelief; or that the number must belong to a knot in the galaxy (IC 3668 is in fact such a knot, and IC 3669 is the south-southeastern arm). But this is all speculation, with none of the principals now alive to tell us what really happened. ===== IC 3668 is a knot in NGC 4618 = IC 3667 (which see). The correct object is marked on a print of the original Bruce 16-inch refractor plate which Wolf examined. ===== IC 3669 is the bright part of the southeastern arm of NGC 4618 = IC 3667 (which see). The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3673 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3674 is a double star, confirmed on a print of the original plate. Wolf's comment "exc[entric] neb *, * 11 sp 1 arcmin" is correct in all respects. See IC 3636 for more about the discovery plate. ===== IC 3675 = NGC 4625. See IC 3667. ===== IC 3676 is a star at Schwassmann's position. In his description, he notes "li[ke] * 13 (perhaps *)", making the identification even more sure. ===== IC 3679 is a double star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3680 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3681 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. Wolf also noted a "* 13 sp 1/2 arcmin"; the image of that star is there on both the print and the DSS. ===== IC 3682 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3685 is a star at Schwassmann's position, perhaps including the very faint star to the southwest, or perhaps involved with a plate defect. His description reads "vF, pL, ?, alpha delta ::". ===== IC 3688 = NGC 4633. Schwassmann's position is good, but it is 10 seconds of time following Swift's for NGC 4633 (actually found by his son Edward. Swift does not say who determined the positions for Edward's nebulae). The descriptions are similar, and Schwassmann has a note about the nearby star, just as Swift does. The identity, apparently first suggested by Ames, is therefore secure. ===== IC 3695 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3699 is a double star, confirmed on a print of the original plate. Though there is a galaxy 0.8 arcmin to the north-northeast, Wolf's mark on the plate, his measured position, and his comment "2 *'[s] 13 np, * 15 n 1 arcmin," all point clearly to the stars as the IC object. See IC 3636 for more about the discovery plate. ===== IC 3700. At one point, I claimed "IC 3700 is a star, confirmed on a print of the original plate." However, going to Wolf's position in DSS shows two very faint galaxies, probably an interacting system. Checking the print again, the smudge there, with Wolf's mark, is exactly on the position of the two faint galaxies. I'm frankly surprised they came through, but there they seem to be. Are they perhaps enhanced by a defect? ===== IC 3703 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3705 is a faint double galaxy, not clearly resolved on the original plate. Wolf must have suspected some irregularity in the image as he calls it a possible spiral. See IC 3636 for more about the discovery plate. ===== IC 3706 is a double star at Schwassmann's position. There may be a defect involved, too, as his description includes the word "dif[fuse]". ===== IC 3707 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3708 is the northwestern arm of NGC 4654. Schwassmann's two positions roughly coincide with the middle of the arm, and his description "pB, cL, Af" (where "Af" means "Nebula similar to the Andromeda Nebula") matches it well enough as it might be seen on a plate taken with a six-inch lens. He has two other entries for NGC 4654 itself, from the same zones on the plate as IC 3708, so the IC object is clearly not a duplicate of the larger and brighter galaxy. ===== IC 3710 is a low-surface-brightness dwarf spiral in the Virgo Cluster. It's structure is similar to the LMC's, but the bar is much smaller, and the knot corresponding to 30 Doradus (NGC 2070) is much larger (though still of low surface brightness). So, the positions for this galaxy are all over its face. I have, as usual, provided the position for the center of the bar. ===== IC 3712 is probably a defect on Schwassmann's plate. There is nothing on the DSS at his position, and there is also nothing at reasonable digit errors that match his description ("vF, pS, Af 42 deg, ??, alpha delta :"; "Af" means "Similar to the Andromeda Nebula"). ===== IC 3715. The IC position is 10 arcmin off in dec. This is a typo in the IC as Wolf's original declination is correct for the object he marked on his plate. See IC 3636 for more about the discovery plate. ===== IC 3716 and IC 3719 are two of Schwassmann's nebulae found on his plates of the Virgo Cluster. He describes both similarly (eF, vS) though adds two question marks after the entry for I3719. He also has a note: "Clearly distinct from one another," probably added since the two objects are separated by less than an arcminute. Unfortunately, there is only one galaxy in the area. Its position is about 10-15 arcsec west of the position for I3719, but the place of I3716 is even further west, and about 30 arcsec south as well. At Schwassmann's RA for I3716, there is a star -- but it is about 30 arcsec north of his Dec. I suspect plate flaws superposed on the galaxy that is there. Since the position for I3719 is closest to the galaxy, I'm going to adopt that number for it -- though with some trepidation. ===== IC 3719. See IC 3716. ===== IC 3721 = IC 3725. The position measured by Royal H. Frost on the Harvard plate is just 6 seconds of time preceding Wolf's more precise position from the Heidelberg Bruce plate. The descriptions are similar, and there are no other objects within 10 arcmin that could be mistaken by either observer for a nebula. The identity is certain. ===== IC 3722 is two blended double stars about 14 arcsec apart. Schwassmann's position falls just between them, and his description "vF, vS, li[ke] * 13" is appropriate. ===== IC 3725 = IC 3721, which see. ===== IC 3730 = CGCG 129-021. Wolf's declination is 30 arcsec off, but his mark on the original plate clearly points to the correct galaxy. ===== IC 3733 may be the star that I've indicated in the position table, though there are two other similarly bright stars nearby, as well as a very faint galaxy (or another star?) that would have blended in with the nearest star on Schwassmann's plate. His description ("eF, S, li * 14") is not very helpful, referring as it does to just a single object. The star I've taken is the closest to his position, though, and does well enough. ===== IC 3737 is a double star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3738 is two stars, enhanced by a very faint galaxy just to the northeast of the southwestern star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3739 is probably a defect on Schwassmann's plate. There is nothing at his position, nor at obvious digit offsets, though there are faint stars and galaxies in the area. ===== IC 3741 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3743 is two stars centered on Schwassmann's position. There are two fainter stars to the southwest, but he makes no mention of these; they may not appear on his plate. ===== IC 3747 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3748 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3749 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3750 is a star, confirmed on a print of the original plate. There is another star 15.5 arcsec south that Wolfgang took as IC 3750. On the red DSS, it does indeed look a little brighter, but the northern star is brighter on the blue POSS1 print, so is probably the object that Wolf marked. See IC 3636 for more about the discovery plate. ===== IC 3751 is a galaxy at Wolf's position, correctly marked and confirmed on a print of the original plate. Wolf's comment "neb * 15 p," however, applies to just a star; there is no nebulosity involved. ===== IC 3752 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3753 is a star, confirmed on a print of the original plate. The "* 14 conn sp" that Wolf mentions in his notes is on the DSS, too. See IC 3636 for more about the discovery plate. ===== IC 3757 is a triple star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. The eastern star is the faintest and looks like a blended double on the DSS. ===== IC 3760 is not IC 815, which see. ===== IC 3764 = IC 817, which see. ===== IC 3765 is a star with a plate defect superposed. The correct object is marked on a print of the original Bruce 16-inch refractor plate which Wolf examined. ===== IC 3768 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3769 is a star, or is perhaps a blended double star. Whatever its nature, the correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3770. There is only a very faint star in Schwassmann's position. It does not match his description ("cF, cS, l 30 deg, ?"), so I suspect that most of the image belongs to a defect. I've nevertheless listed the star as it is within a standard deviation or so from Schwassmann's position. ===== IC 3771 is a galaxy with a plate defect superposed. The object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3772 = CGCG 188-020 = MCG +06-28-028. The IC number has sometimes been mistakenly attached to DD0 47 = UGC 07949 = MCG +06-28-030 which is 3 arcmin south-southeast. But Wolf's position is good, and he has marked the correct galaxy on his original plate. ===== IC 3773 is a pretty low surface brightness late-type galaxy in the Virgo Cluster, found by Frost on a Harvard plate. There is a 15th magnitude star superposed on the outer boundary of the galaxy about an arcmin northeast of the nucleus. Even though Frost claims that the galaxy is Sn 150, his position is about 2 arcmin southwest of Schwassmann's, which is within a few arcsec of the star. This suggests that Frost should be credited with the discovery of this galaxy rather than Schwassmann. ===== IC 3777 is a star at Schwassmann's position. Wolfgang, in his first list, took VCC 2054 as the IC object, but this is wrong. The galaxy is over an arcmin away from the nominal position, and neither RA nor Dec has reasonable digit errors to explain the offset. ===== IC 3780 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3781 is a double star, confirmed on a print of the original plate. It is quite faint on the DSS, but Wolf's position is very close and he mentions the stars to the north and west in his notes. See IC 3636 for more about the discovery plate. ===== IC 3782 is a star. Even though Wolf's declination is 30 arcsec too large, the correct object is marked on a print of Wolf's original plate. So, there can be no question about the identity. ===== IC 3785 is a galaxy, and there may be a faint defect superposed on the discovery plate. The print of the plate that I looked at is not clear enough to be sure. See IC 3636 for more about the discovery plate. ===== IC 3787 is a double star. The object is blended into a single image on a print of the original Bruce 16-inch refractor plate. Wolf's mark points unmistakeably at the correct object. The only mistake here was mine in giving only the brighter eastern object the IC number when I first went over the field. ===== IC 3790 is a star exactly at Schwassmann's position. Even though he describes it as "eF, vS, ??" -- the "??" indicating considerable doubt about the nebulous character of the object -- there is no doubt about the identity. The position is too close to a star very similar to others that Schwassmann, working at the limit of his plates, mistook for faint nebulae. ===== IC 3791 = NGC 4695. Swift found the IC object on 23 May 1897. That same night, he found two other objects: I2976 and I4205 (both of which see). I2976 is NGC 3979, and I4205 is IC 853. For I3791, he notes "[NGC] 4732 in field." That can't be right as N4732 is 1.5 degrees south of Swift's position for I3791. (The galaxy in the field is actually N4686). This was not a particularly good night for Lewis Swift. His position for I3791 shares with that for I4205 a declination which is about five arcmin too far north; the right ascensions are very close to correct in both cases. (I2976, on the other hand, has a declination that is very close to the modern value, while its RA is 1.5 minutes too small.) Since his descriptions are also appropriate for the galaxies, I have little doubt about the identities I've suggested here. ===== IC 3792 is two faint stars, probably with a defect involved, too. Schwassmann's position is about 20 arcsec to the south. There is an extremely faint galaxy in the area, too, but it would not have showed up on the plate from the 6-inch refractor that Schwassmann was using. ===== IC 3794 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3796 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3797 must be a defect on Schwassmann's plate. His description is telling: "F, pS, perhaps FN, like an asteroid trail, geom N pt". I'm not sure about his last phrase, but the first three make it clear that he was looking at an elongated object. Since there is nothing like that at his position, nor at reasonable digit offsets, this is most likely a plate defect. ===== IC 3798 is a star at Schwassmann's position. ===== IC 3801 is another defect on Schwassmann's plate. He describes it as "cB, pS, li * 95 [sic]". There are no stars this bright in the area, and there are none either at positions where digit errors might put them. ===== IC 3802 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3803 is a star, probably with a defect involved. Schwassmann's position is good, but his description "eF, pL, ?, alpha: delta:" suggests that the object was more extended than his usual star. ===== IC 3804 = NGC 4711. The correct object is marked on a print of the original Bruce 16-inch refractor plate which Wolf examined. Neither he nor Dreyer realized that the object is NGC 4711 in spite of the nearly identical positions and Wolf's clear description of this as quite a noticeable nebula on his plate. ===== IC 3805 is a double star about 25 arcsec north of IC 3802, another star (which see). The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3807 may be NGC 4705. It is the only galaxy within several degrees of Swift's position that comes close to matching his description: "eeF, L, eE; 7m * nr s little f." However, the star is northeast, not south-southeast as Swift implies. If so, this just another of his mistakes in noting relative positions. I looked for another galaxy at a declination digit (10 and 20 degrees south) and sign (+3 rather than -3) away from his nominal position -- nothing at all. I have not yet checked at digit errors in RA hours, but there is certainly nothing at +- 1 minute or +- 10 minutes of time. My feeling is that this is another case like IC 3166/3180 (which see): the NGC galaxy is probably Swift's object, but we have only circumstanstial evidence of the match. So, I am not going to put the IC number on the NGC number, even with a question mark. With the position so far off, and the direction of the star being different from Swift's description, I am just not comfortable with the hypothesis. The magnitude of the star is V = 9.22, by the way, and it is 4.85 arcmin from NGC 4705. If this is Swift's object, the star would have been well within his field radius of 16 arcmin, and the magnitude at least in the ballpark for a rough estimate. ===== IC 3810 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3811 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3817 may be a double galaxy, though it looks more like a single, somewhat peculiar, blue galaxy on POSS1. See IC 3636 for more about the discovery plate. ===== IC 3820 is a fairly faint galaxy with a plate defect superposed on its image on Wolf's original plate. The defect pulls Wolf's position (copied correctly into IC2) 10 or 12 arcsec south off the galaxy. The object is marked on a print of the original plate. ===== IC 3821 is a double star, confirmed on a print of the original plate. Its image is blended on DSS1, and when I first went over the field, I mistakenly called it a single star. See IC 3636 for more about the discovery plate. ===== IC 3823 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3827 = IC 3838, which see. ===== IC 3829. The identity is not sure. Swift has left us three different positions for his 19th nebula from his 7th list from Echo Mountain. He found the galaxy on 31 January 1898, within just a few months of his final nebular discoveries (the positions are in the table). The IC description reads "B, S, lE, *9 sf [?119deg 14.5']" (Dreyer's query, not mine). His description in the big AN "Catalogue No. 11 ..." reads simply "B, S, lE", so the additional information must come from one of the smaller lists. It is found in the Monthly Notices (58, 332, 1898) version where he adds "9m * near sf". After a search of the area, Andris and I settled on ESO 442-G026 as Swift's object. This is the brightest object around, it is an even 50 seconds of time from one of Swift's positions -- but it does not have a bright star nearby. The brightest star to the east is a 10th or 11th magnitude star 6.5 arcmin east. There are somewhat fainter ones 6 arcmin southeast and south-southwest. The other candidate is ESO 442-G024: larger, fainter, with a lower surface brightness, and surrounded by 9th magnitude stars: 2.5 arcmin northeast, 4 arcmin south, and 6.5 arcmin southwest. Swift would have seen all of these and would have commented on them. He would also have called the galaxy "eeF, vS" at best. Still, I suppose it is possible that his is his object, so I've put it in the table, too, though with question marks. ===== IC 3830 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3833. The IC identity of this galaxy is not in question. Bigourdan's measurements in April 1895 are very good (his comparison star has one of the highest proper motions I've encountered in doing this work -- over 0.42 arcsec per year), so we cannot mistake the galaxy he found. Herbert Howe ran across the same galaxy, but thought it might be one of the pair, NGC 4722 and 4723 (which see), that Tempel found following NGC 4714. Dreyer put Howe's object into the IC notes as "NGC 4722-23", apparently without noticing the coincidence of Bigourdan's and Howe's positions. MCG certainly picked up on it, however, so has N4722 = I3833. Working on ESGC, I made the same assignment of the numbers, but clearly did not do much digging into the literature (though I did translate Tempel's published note for N4722 and 4723). In any event, I see now that we actually do not know for sure which objects Tempel saw. So, we may not be correct in equating one of them with IC 3833. Thus, my liberal use of question marks in the position table for the two NGC numbers. ===== IC 3834 is not, as so often supposed, NGC 4740 (which see; it is actually a reobservation by Swift of NGC 4727, the brightest galaxy in the group of four here). Nor is it NGC 4726 (which also see), as first suggested by Howe and taken up by Dreyer in a couple of IC2 notes. Bigourdan wisely threw out all the NGC numbers for his observation of this galaxy (or he was utterly confused and simply ignored them) and declared it a "nova", even though Howe had obviously seen, too. ===== IC 3838 = IC 3827. Bigourdan made a mistake of +1 minute in the RA of his comparison star. Otherwise, his four observations on 14 Apr 1895 are a detailed and accurate account of the galaxy, the star to the south (also noted by Howe), and the comparison star. ===== IC 3839 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3840. Though Wolf comments "* sp inv," the object there is actually a part of the galaxy, a rather patchy IB(s)m IV, itself. See IC 3636 for more about the discovery plate. ===== IC 3841 is a double star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3845 is a star. There is a very faint galaxy just to the southeast of the star, but there is no trace of it on the print of the original plate. The star is marked on that print. ===== IC 3846 must be another defect on Schwassmann's plate. His description, like others for defects, would make this an outstanding object that the Herschels would be ashamed of for missing: "B, pL or pS, N = * 9.2". Needless to say, there is nothing like this in the area, nor at any reasonable digit errors. ===== IC 3847. Wolf's comment "neb * 15 sp" is slightly incorrect: the star is not nebulous. See IC 3636 for more about the discovery plate. ===== IC 3848 is a faint double galaxy, not resolved on the original plate. Wolf noted it as being elongated, however. See IC 3636 for more about the discovery plate. ===== IC 3849 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3851 is a star, with a defect superposed on the image, confirmed on a print of the original plate. Wolf's comment "* 12 s" is also correct. See IC 3636 for more about the discovery plate. ===== IC 3854 is the larger of two galaxies. Wolf actually saw the second on his plate, but called it a "* 15 f." ===== IC 3858 is a star, confirmed on a print of the original plate. Also, Wolf's comment "* 13 sp 1/3 arcmin" is correct. See IC 3636 for more about the discovery plate. ===== IC 3860 is a faint, little galaxy. I suspect that there is a defect enhancing its image on Wolf's original plate. Otherwise, I don't see how he could have picked it up. It is, however, close to his position, so I've included it in the table. ===== IC 3862 = UGC 08023 has an eccentric nucleus, noted by Wolf as an "att * 15." ===== IC 3863 is a galaxy with a star superposed. The object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3864 is a faint galaxy, with a star superposed, not resolved on the original plate (my original classification as a double galaxy was wrong). Wolf noted the star 0.5 arcmin south, so there is no question about the identity. See IC 3636 for more about the discovery plate. ===== IC 3866 is a faint double galaxy, not clearly resolved on the original plate. Wolf must have noticed some irregularity in the image, however, as he suggested it might be a cluster. Perhaps the low surface brightness spindle to the southwest is included in the image, too, though it does not show up as an individual object on the print. See IC 3636 for more about the discovery plate. ===== IC 3877. Wolf's position is exactly 7.0 arcmin north of the true position -- the correct object is marked on his plate. I suspect this results from a measuring error which placed the object 2 cm closer to the top of the plate than it really is. See IC 3636 for more about the discovery plate. ===== IC 3878 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3881 is the northeastern of two faint galaxies, and is clearly marked on Wolf's plate. He describes it as "vF, vS; long chain? attached north (remarkable), chain? connecting [to I3877]." There is a trace of a very faint defect, or of a random clumping of photographic "grain," on the print of Wolf's plate which I examined, but certainly no "chain" of galaxies appears on POSS1. For more about the discovery plate, see IC 3636. ===== IC 3886 has a faint star superposed, but it is not clearly seen on the DSS. Wolf's note reads "Ch!! conn 1'n, &&, viF." This becomes, "Very remarkable chain connecting 1 arcmin north, very irregular figure." The print of Wolf's original plate shows the galaxy only faintly, but his mark points exactly at it. The two stars about an arcminute north are not connected to it in any way on either POSS1 or POSS2, so the connection that Wolf saw on his original plate must be a defect. It does not show clearly at all on the print of his plate. See IC 3636 for more about that plate. ===== IC 3887 is a double star, though the northwestern star is enough fainter that we missed it on the POSS1 O print. We called it a single star for several years. The correct object is clearly marked on a print of the original Bruce 16-inch refractor plate -- the two are completely merged there. ===== IC 3889 is probably a single star, though it may include two other stars and a galaxy within an arcminute to the north. None of the objects is clear on the print of the original plate, nor is it clear to which of these objects Wolf's mark points. However, his position is for the southern star, so that is probably the object we ought to take. ===== IC 3891 is a galaxy. Though I took it to be a star with a plate defect superposed during my survey of the IC objects in Wolf's fifth list, this is clearly incorrect (thanks to Malcolm Thomson for catching the mistake). The object is marked on a print of the original Bruce 16-inch refractor plate which Wolf examined, but is not clearly seen on the print. It is possible that it appears stellar on the POSS1 blue print which I looked at, but it is more likely that I made a simple mistake. DSS clearly shows it to be a galaxy. ===== IC 3893 is marked on the print of the original plate 3.5 arcmin north of Wolf's published position. Since other of the nebulae in this list are also off by the same amount (e.g. IC 3919), I think that the discrepancy represents a digit error in Wolf's y-axis measurement. The galaxy is the largest of three; the other two are just northwest of I3893, but only one is (faintly) visible on Wolf's plate. ===== IC 3894 is a double star, confirmed on a print of the original plate. Wolf notes a 15th magnitude star to the northeast; that star is there. See IC 3636 for more about the discovery plate. ===== IC 3898 is a faint galaxy with, according to Wolf, an "att eF * pr." The "star," however, is a defect on the original plate. It is just seen on the print of this plate that I examined. ===== IC 3901 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3902 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3903 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3904 = CGCG 188-029. Wolf correctly describes this as a spiral, but he has the sense of spirality backwards. ===== IC 3905 is a faint triple galaxy -- probably an interacting system -- not resolved on the print of the original plate. A fourth galaxy, not on the print, is about 40 arcsec on to the southwest from the brightest component. See IC 3636 for more about the discovery plate. ===== IC 3906 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3910 is a double star. Wolf's comment reads "? neb **" -- there is no nebulosity associated with the double. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3911 is two galaxies, or a galaxy and a star, whose images are merged on the original Bruce 16-inch refractor plate which Wolf examined. The object is marked on a print of that original plate where it appears to be single. The second galaxy is very compact if it is indeed a galaxy. ===== IC 3912 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3914. On the DSS, this is a double object, with a star being about 12 arcsec northwest of a galaxy. On the print of the original plate, there is an apparent plate defect superposed. The defect -- which may only be present on the print of the original plate -- stretches to the northeast from the galaxy. Wolf's mark points at the galaxy itself. My earlier assessment of this as a single star and a defect may be the result of the appearance of the object on the POSS1 blue print. On the red print, and on the DSS, it is clearly a galaxy with a neighboring star. My thanks to Malcolm Thomson who called my attention to the discrepancy. ===== IC 3915 is the northern of two stars, confirmed on a print of the original plate. Though Wolf's position is in error by exactly 10 arcmin in declination -- clearly a typo -- his mark on the plate, and his comment "inv * 14 s" both refer to the correct object. See IC 3636 for more about the discovery plate. ===== IC 3917 is a star, confirmed on a print of the original plate. This number has occasionally been mistakenly assigned to the galaxy IC 3918 (e.g. RC1), but Wolf's position corresponds to the star he has marked on his plate. See IC 3636 for more about the discovery plate. ===== IC 3918, a real galaxy, has occasionally been assigned the number IC 3917, which see. I3917 is actually a star. ===== IC 3919 is marked on the print of the original plate, and is 3.5 arcmin north of Wolf's published position. Since other of the nebulae in this list are also off by the same amount (e.g. IC 3893), I think that the discrepancy represents a digit error in Wolf's y-axis measurement. There is a larger but fainter galaxy about 1.5 arcmin east of the IC galaxy. It is not visible on the print of the original plate. See IC 3636 for more about the plate. ===== IC 3923 is a double star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3925 is a double star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3926 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3932 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3933 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3935 = NGC 4849. The problem here is that the galaxy is in a crowded area of the sky (the Coma Cluster), and d'Arrest's position is 4 arcmin south of the galaxy. This was corrected by Spitaler and mentioned in the first IC by Dreyer, but he did not notice that Javelle's object was exactly at Spitaler's position, too. So, two numbers. ===== IC 3936. The position corresponds to a single star about 30 arcsec south of a line of three stars. The mark on Wolf's plate is not clearly pointing at one or the other of these, however, and his description is more apt for the line of stars (not resolved on the original plate). Wolf also noted the brighter star 1 arcmin following his object, again matching the line of stars better than the single star. However, the single star to the south is only 4 arcsec away from Wolf's position. Given that his mark is ambiguous, I've taken all four stars as IC 3936, and labeled them with my usual directional flags. See IC 3636 for more about the discovery plate. ===== IC 3938 is a star, confirmed on a print of the original plate. Wolf correctly comments "* 13 sp." See IC 3636 for more about the discovery plate. ===== IC 3939 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3941 is a galaxy. There is a defect on the print of original Bruce 16-inch refractor plate; Wolf's mark points to the defect, but also at the galaxy. Neither is very clear on the print, but Wolf's position is right on the galaxy. Thanks to Malcolm for catching my earlier error for this object. ===== IC 3942 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3951 has a defect superposed on the original plate, clearly visible on the print I examined. Wolf noted the second image, and suggested that the object might be a double star immersed in nebulosity. No trace of the second "object" appears on POSS1, however. See IC 3636 for more about the discovery plate. ===== IC 3961 = NGC 4861, which see. The entire galaxy is clearly marked on the original 16-inch Bruce plate (one of the "stars" mentioned in Wolf's description is the bright HII region), and Herschel's description also clearly applies to the entire galaxy. The identity is certain, and the CGCG's contention that N4861 is only the bright HII region in IC 3961 is wrong. ===== IC 3962 is a star, confirmed on a print of the original plate. See IC 3636 for more about the discovery plate. ===== IC 3964 is a star. Kobold's offsets, re-reduced with respect to the AC 2000.2 positions for his comparison stars, point directly at it. This is just one of about 15 new nebulae that he found during his work in the Coma Cluster in the spring of 1896. ===== IC 3969 is a triple galaxy -- with a foreground star just west -- in the core of Abell 1657. Wolf found two other nebulae (IC 3971 and IC 3978) -- and a star, possibly blended with two galaxies (IC 3984) -- nearby, and suggested that they formed a chain. He encompassed all with a single mark on his plate; only IC 3969 and IC 3984 are clearly visible on the print. See IC 3636 for more about the discovery plate. ===== IC 3970 is probably the star near Wolf's position. However, that position is far enough off the star toward another one to the west, that I wonder if it applies to both stars. If so, then Wolf's position angle is close to being correct, too. But then, Wolf's "* 15 att p" is lost. So, I favor the single star explanation. At least one object is marked on a print of the original Bruce 16-inch refractor plate which Wolf examined, but the print is not clear enough to show the two stars separately, or any defects that might be involved. ===== IC 3971 is a galaxy in Abell 1657. See IC 3969 for more. ===== IC 3972 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3974 = NGC 4947. Swift's position is just 5 minutes of time smaller than that for NGC 4947. Since there is nothing at Swift's position, the identity, while not secured by comments about the star field, is pretty certain. These sorts of large errors occur frequently in the observations from Swift's last years; he found this object on 28 March 1898, less than two months before his last recorded discovery. ===== IC 3977 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3978 is a galaxy in Abell 1657. See IC 3969 for more. ===== IC 3979 is a star with a defect superposed. The position I measured refers to the star alone. There is another star within an arcminute to the north, and I mistakenly took that as the IC object when I went over the field earlier. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3981 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3982 is a star, flanked to the southwest and northeast by two brighter stars, both noted by Wolf. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3983 is a double star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3984 is probably a blended image, a star with two galaxies about 28 arcsec west. While Wolf's position is for the star, the brighter galaxy looks like it is the object marked on the print of the original plate. I've given positions for all three in the main table. ===== IC 3988 is a star. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3989 is a star about 1.8 arcmin south of its listed position. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3992 is a star, the eastern and slightly brighter of two. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3995 is a star about 9 arcmin north of its listed position. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3996 is a blended double star on the DSS1 image. The two images are close enough that I called them a single star when I first went over the field. The correct object is marked on a print of the original Bruce 16-inch refractor plate. ===== IC 3999 is probably identical to NGC 4862 (which has its own story). Bigourdan has only a note on the object in his big table, claiming the object to be +30 seconds and +3.7 arcmin from BD -13d 3633. This observation is dated 16 April 1895. However, refering to his table of novae, Bigourdan makes the date 12 May 1885. There is no other trace of this observation in his published tables, including his list of supplementary observations in Appendix 8 of his introduction. So, the 1895 observation is all that we have to go on. At Helwan and Mt. Wilson, observers chose the star close to the nominal position as the object. Wolfgang Steinicke and I made a different choice, the faint galaxy 7 seconds east and 4 arcmin south of the nominal position. Finally, Malcolm Thomson noticed that if the sign of Bigourdan's estimated RA offset is changed to a minus sign, the position is close to NGC 4862, a faint spiral found by Frank Leavenworth at Leander McCormick (the galaxy is positively identified by Leavenworth's sketch; as usual, the nominal position is off in RA). Malcolm's idea is given added support when we look at Bigourdan's attempts to find NGC 4862 -- he did not find the galaxy on two nights. On the first night, however, he searched at the offset of +10 seconds and +4 arcmin from the same BD star, and made a specific note that he did so. This is the wrong direction, however, so on the second night, he searched at -10 seconds and +4 arcmin. It was on this second night that he "... suspected a trace of nebulosity in the neighborhood of a star, magnitude 13.4, located at ..." the offsets noted above. Since he had his offsets confused for one night, it seems reasonable that he might have done the same the second. In any event, reversing the sign of his estimated RA offset puts his suspected object within an arcminute of NGC 4862. Thus, the identity is reasonable, so I've adopted it. =====