NGC 2006. Brian Skiff has recently (July 2006) called this "cluster" to my attention. At the NGC position there are actually two very small, compact clusters, probably both globulars. Brian noted that the northern is certainly [SL63] 538, while the southern is almost always called "NGC 2006". Mati Morel and Jenni Kay certainly do this in their Atlases, as does Brent Archinal in "Star Clusters" and Andris Lauberts in ESO. But when I looked at JH's observations, I found a very different story. Here is what I wrote to Brian: JH has two observations for N2006 (precessed to J2000): 05 31 19.4 -66 57 27 A very small nuclear knot in an extremely rich assemblage of stars and clustering groups which fill the field. 1834 Dec 23 05 31 18.2 -66 59 11 A small highly condensed knot in an immensely large and very rich cluster, which fills much more than the field, and is like the Milky Way. 1837 Jan 03 He clearly saw the same (large!) thing both times. The position for the first more or less corresponds to the northern cluster, and that for the second to the southern. So, I think that he either did not separate the two -- unlikely, since you saw both clusters with a much smaller telescope -- or he was so impressed by the much larger background star cloud that he simply took both clusters to be a part of it. It is curious, though, that he didn't mention the "knot" as a double object. Looking at the field on the DSS, I would guess that JH's "object" goes all the way to include NGC 2002 to the northwest, and a similar distance to the southeast [roughly 15 arcmin by 7 arcmin]. I don't think that it extends as far southwest or northeast, though JH does not mention any particular elongation. So, I'm pretty sure that the JH/GC/NGC numbers are meant to include both clusters and much more of the Large Cloud besides. Though Brian suggests keeping the southern cluster as NGC 2006 for consistency with the modern literature, I've included both clusters in the position list with notes (hopefully) clarifying the identification. I've also adopted the rounded mean position of the two clusters for "NGC 2006" itself. ===== NGC 2017. JH calls this "A fine clustering group of large stars" when he saw it on 11 Dec 1835. But there are only 6 stars here brighter than V = 11.3, four of them brighter than V = 9.0. The four would nevertheless make a striking group at the eyepiece, and I'm a bit surprised that this asterism is not better known. Is it a real cluster? Probably not. One of the bright stars has a relatively large proper motion of 67.2 milliarcseconds per year, but the other proper motions are all six to twenty times smaller and not in any systematic direction. Brian Skiff comes to a slightly different conclusion; he also considers the photometry. His discussion is at ftp://ftp.lowell.edu/pub/bas/ocpos/n2017.pos Whether a real cluster or not, this is worth a look now and then. ===== NGC 2029 and NGC 2030 have their positions interchanged in GC and NGC. They are correctly given in CGH, so the error occured when JH was assembling the GC. ===== NGC 2030. See NGC 2029. ===== NGC 2039 (= h 366) was described by JH as "A large tract of stars filling many fields. It extends much further in RA." He has a second concordant observation: "A large ill-defined tract of loose stars, neither rich nor condensed," though for this one, he made an estimate of only the NPD. Just such a configuration, roughly 30 arcmin across in RA and 10 arcmin in Dec, is centered two or three arcmin north-northwest of JH's single position. It is a well-scattered group of about 30 stars ranging in magnitude from 8 to 13. I doubt very much that it is a true cluster. However, JH called this H VIII 2 in both observations in his 1833 catalogue. That this is probably not the case was realized by JH himself as H VIII 2 (NGC 2063, which see) and h 366 were given separate GC numbers. WH described his object as "A small cluster of very small scattered stars" and gave it a position (from two observations) nearly 3 minutes of time following and 8 arcmin north of JH's later position for h 366. Dreyer followed GC, but neither he nor JH mention the initial confusion of the two objects. ===== NGC 2045 = Lalande 10842 = SAO 094827. JH has this simply as "A star 8-9 mag with faint nebulosity." It is barely possible that there is indeed a bit of faint nebulosity around the star, but it is very difficult to see on the POSS1. ===== NGC 2050 was found during JH's stay at the Cape of Good Hope. Curiously, he does not give a sweep number for it in his main table, nor does he give a zone number for it in his table of LMC objects. However, in a note to that table (in which it is No. 628), he says that this object and several others near 30 Doradus (NGC 2070) had "... their places deduced from a very careful and deliberate drawing of the neighbourhood of 30 Doradus ..." In his text, he says that the drawing was made over several nights, but specifically mentions 29 November 1834, and 21 and 22 December 1835 as nights on which he worked on the drawing. So, it seems likely that NGC 2050 was first seen on one or another of these nights. ===== NGC 2054 is a group of 6 faint stars found by George P. Bond, then director of Harvard College Observatory. In his small "Comet-seeker," the grouping appeared nebulous, and he gave it only an approximate position. Dreyer himself saw the nebula and commented, "... at times, I thought it was a very small cluster, but it is doubtful." Nevertheless, he gave an accurate micrometric measurement of a star, 9-10th magnitude, in position angle 0.5 degrees and distance 404.0 arcsec. The star is indeed there, and was later seen by Howe (MN 58, 515, 1898) who misattributed it to Bond, but saw only "three small stars" in the place. Bigourdan provided a corrected position for the asterism, quoted by Dreyer in IC2. ===== NGC 2063 may be the small grouping of 7-8 faint stars at WH's place, though there is another larger clump with brighter stars about 8 arcmin to the south-southeast. Neither is likely to be a true cluster, and I am not sure that either one is the correct object. Taking WH at his word, though, I've tentatively assigned the NGC number to the stars at his place. JH did not see this clump, but mistakenly asigned the number H VIII 2 to h 366 (= NGC 2039, which see) in his 1833 catalogue. He separated the two objects for the GC, and Dreyer followed his lead. ===== NGC 2064. See NGC 2067. ===== NGC 2067 is a part of the large complex of nebulae around M78 = N2068. Found by Tempel, neither the position nor the description makes it really clear which part of the nebula he saw. The first position I give in the main table is for a large patch of pretty low surface brightness nebulosity about 5 arcmin northwest of M78. But this is not the brightest nebulosity in the area. That is a knot about 3 arcmin southwest, the brightest part of a long faint streamer pointed toward NGC 2064. This, however, is much more east than north of M78, while Tempel says that M78 is to the south. So, a bit of a mystery here -- which part of the nebulosity was Tempel refering to? I've stuck with the larger more northerly end of the nebula, but could well be wrong, so have also put the southern knot in the main table. ===== NGC 2068 = M 78. See NGC 2067. ===== NGC 2107. See NGC 2171. ===== NGC 2129 appears to be a cluster of about 30 stars scattered around two bright ones near the center. However, neither the UCAC2 proper motions, nor multi- color photometry (see J. H. Pena and R. Peniche in Rev. Mex. A&A 28, 139, 1994) support the idea that this is a true physical cluster. Instead, it seems that this is a random clumping of stars at different distances, accidentally rich enough to pass for a real cluster. James Kaler's article in S&T, Feb 2005, page 90, called attention to the purely optical nature of this object. ===== NGC 2132 may be a cluster centered a few arcmin following JH's position. That position applies to the "Chief * of a cluster of 8th class of about a dozen bright and some smaller stars." This is just what we see on the sky today. The stars are scattered over an area of 17 arcmin by 11 arcmin. They stand out enough from the field that I'm a bit surprised that Lauberts did not pick them up for the ESO list. JH's "chief star", by the way, is SAO 234207 which is within a few arcsec of his position for it. ===== NGC 2139 = IC 2154. Dreyer has a note in his 1912 edition of WH's Scientific Papers on this object. Taken from WH's note in the sweep, it reads "The A.R. cannot be above 10 or 15 s out; the roller went off the apparatus which occasions the uncertainty." The RA is actually 24 seconds out, and the dec, due to another unspecified error, is 8.5 arcmin off. Dreyer was further able to identify a star in the sweep that was closer to the galaxy than WH's "official" reference star, delta Canis Majoris. Comparison with this star led to the correct position. However, he had not yet done this when Howe and Bigourdan tried to find the NGC object near WH's place -- not surprisingly, neither succeeded. What is surprising is that when Lewis Swift came across the galaxy over a century after WH, he did not make as nearly as large an error in its position as WH. Swift's positions from his last nights in 1897 and 1898 at Lowe Observatory on Echo Mountain are nortoriously bad. But for this object, he actually came within 14 seconds in RA and 1 arcmin in Dec. Herbert Howe pinned the galaxy down with a micrometric observation and it was that position that Dreyer adopted for IC 2154. Dreyer himself discovered the identity when he fixed WH's position for the NGC object. ===== NGC 2142 = 3 Moncerotis = SAO 151037. JH says, "I am sure this star has a faint nebulous atmosphere 2 or 3 arcmin in diameter. Eye-glass examined, not dewed." This brightest part of the nebulosity is lost in the glare of the star on the POSS1, but a very faintly extended cloud can just be seen on the red plate. It would be nice to have independent confirmation of this. ===== NGC 2143. This is a cluster of pretty bright (V ~ 9 - 13) stars covering an area about 12 arcmin by 10 arcmin across. While JH puts the center close to the brightest star (SAO 113401), I make it (on the POSS1 print) about three arcmin to the west. Brian Skiff puts the center (using the DSS) seven arcmin to the north, nearly on the edge of the cluster. This must be a typo of some sort. A curiosity: JH's original description contained the note, "... place of a * 10m in M." Somehow, this metamorphosed into "stars 10" in GC and NGC. This may have led in part to RNGC's failure to find the cluster. ===== NGC 2163. The NGC NPD is incorrect, being one of Dreyer's very few transcription errors. He corrects the mistake in the IC2 Notes. The object is a striking example of a bi-polar nebula with fans of nebulosity extending north and south from the central star. Stephan's position is good. ===== NGC 2167 is probably SAO 132848; it is certainly not H IV 44. This error comes from JH who equated his own h378 with his father's "planetary" more than 10 arcmin south-following his (JH's) position. Dreyer followed JH in NGC, but when he prepared WH's papers for their re-publication in 1912, he realized that WH's description as well as position did not agree with JH's. Dreyer gives some additional information in his note in WH's Scientific Papers, and also suggests there that WH actually observed a nebulous star about 70 seconds of time following JH's position. This suggestion was the source of my own comment in the preliminary version of ESGC that the RA of N2167 is 1 minute of time too small. I think now that Dreyer and I were wrong. The description of IV 44 fits IV 19 = NGC 2170 very nicely, and the RA's are the same. The Dec's are about 8 arcmin different, and IV 19 was not seen in the sweep in which IV 44 was found. Therefore, it is likely that the only error in NGC is calling N2167 "IV 44." Is there, however, a problem with JH's observation? The star at his position has almost no trace of nebulosity around it. Yet JH does not mark the position as uncertain, and that position is within 20 arcsec of the true position of the star. And JH calls it a "star 7 m;" its V magnitude is 6.9. By contrast, the star in NGC 2170 is 9th magnitude, and the star that Dreyer suggested as IV 44 is 11th magnitude. Perhaps there is a trace of nebulosity hiding in the overexposed image of the bright star. A close visual examination is needed. ===== NGC 2170. See NGC 2167. ===== NGC 2171. I had given this up for lost, but Mati Morel found a star cloud in the LMC that fits pretty well: the two clusters SL 691 and 692 and the surrounding area. The contrast with the background of the LMC is subtle, but it fits JH's description very well. JH has it as "eeF, vL, R, glbM, 4'" from a single sweep (number 657 on 16 Dec 1835). The object marked in the Hodge-Wright Atlas is a faint star about 2 arcmin south of JH's position; ESO apparently adopted this identification, too. In "Star Clusters", Brent makes this KMHK 1573 at 05 59 03.8 -67 53 56 (B1950.0), with no explanation of the 2.5 degree difference from JH's declination. Mati had earlier suggested that this object is identical with SL 809, a small, faint star cluster in the LMC. While the position is not too far off (34 seconds in RA, and 3.8 arcmin in Dec), I was skeptical because this cluster is only 0.7 arcmin across, certainly not an object that JH would have called "vL ... 4'". I had finished up my earlier note by saying, "So, the only other possibility that I can see is that JH made a 10 or 20 minute error in his RA, and that his observation applies to one of the star clouds in the eastern end of the LMC's bar. However, this is such a stretch that I'm not going to list any of these star clouds in the main table." Mati took me at my word, though, and found a star cloud that matches JH's declination and his description almost perfectly. This is by no means, though, a solid identification. NGC 2107 is just one minute of time preceding the star cloud, and I wondered why JH did not mention that in the same sweep. However, looking at his list of nebulae in the LMC, it's obvious that in any given sweep, he skipped many that he recorded in other sweeps. The nebulae and clusters were just coming by too quickly for him to record them all, so he went over each area of the LMC several times to be sure to catch all the objects. In any event, Mati's star cloud, with its two embedded Shapley-Lindsay clusters, is the best candidate I've seen for this object, so it's in the main table with just a colon. ===== NGC 2174 is one of the knots in NGC 2175, which see. ===== NGC 2175 is a very large roughly circular emission nebula which also includes NGC 2174 and IC 2159 (both of which see), and a star cluster which has inherited the NGC number, though there is no mention of it in the discovery notes. The nebula is centered on SAO 078049, though the brightest knot (which Bigourdan took for N2175; hence, the "corrected" RA in the IC2 Notes) is about three arcmin to the west-northwest. Auwers's note makes it clear that NGC 2175 is much more than just the knot: he gives dimensions of 25 arcmin by 8 arcmin, and specifically adopts the position of Lalande 11668 = SAO 078049 as that for the object. I have followed his lead. ===== NGC 2189 is described by J.H. Safford as "Two clusters, seen 1863 March 19 near two stars of the 10-11th magnitude" with the "Great Refractor" at Harvard College Observatory. (The NGC description confuses the stars with two others in Safford's description of another cluster NGC 2198, which see). Curiously, he gives positions of the two stars, but not of the clusters. So, we can identify the stars with certainty (Safford's positions, precessed to B1950.0, are 06 09 15, +01 07.7 and 06 10 17, +01 09.0), but not the clusters -- there is nothing in the area aside from random clumpings of field stars. However, two of the clumpings -- listed in the main table as possibly being the correct objects -- may be the one's Safford noted. Both are extended roughly north-south, with the first having a diameter of about 6 x 3 arcmin and including only a dozen stars, and the second 3 x 2 arcmin, again with only a dozen stars, fainter than those in the first group. Neither is likely to be a real cluster. Are these the right objects? We need observations, and a look at Safford's original observing records, to be sure. ===== NGC 2195 is a double star; there are two fainter stars near to the north that may have added to the illusion of nebulosity. The object was found by J. G. Lohse who also noted the 10th magnitude star 31 arcsec north. It is this star that clinches the identification since Lohse's RA is about 3 arcmin too far west. RNGC picked the wrong object. ===== NGC 2198. Described as "A cluster, seen 1863 March 19 by J.H. Safford, between two stars ... With the Great Refractor" at Harvard, the NGC position actually corresponds to a field with fewer than the average numbers of stars. As with NGC 2189 (which see) Safford measured the two stars (one is 10-11 magnitude at 06 10 57, +01 00.1; the other is 9-10 magnitude at 06 11 42, +00 59.3, both for B1950.0), but not the cluster. I see nothing in the field on the POSS1 prints that looks like a cluster. Perhaps a visual observation can turn up something. ===== NGC 2218 is only an asterism of four stars. It is one of the "nebulae" recorded in the Markree Catalogue, pulled out by Auwers in his 1862 compilation of the nebulae found by others than the Herschels. Auwers looked for it, but had to note "Invisible in the Heliometer." The original position is good. ===== NGC 2220. JH calls this "A poor, very coarsely scattered, but brilliant cluster of 8th class. Place of a star 8m = B 1222, the chief of cl." The star is SAO 217873 and is well off the center towards the southeastern edge of a clump of 7-8 stars. Roughly 15 arcmin to the northwest is a similar clump of 4-5 stars; I wonder if JH meant to include this as well. I've included positions for both clumps and the entire grouping in the table. In any event, the stars probably do not constitute a real cluster. We'll need to check their proper motions to be sure of that, however. ===== NGC 2224 is perhaps the elongated gathering of stars centered about three arcmin southwest of the NGC position. It looks to me like a random fluctuation in the Milky Way, though it is overlain by an extremely diffuse band of nebulosity. This area should be examined telescopically -- the POSS is crowded with faint stars. ===== NGC 2225 and NGC 2226 have sometimes been considered to be the same object. In fact, the latter number refers to the compact core of the cluster, apparently unresolved in the 5- or 6-inch refractor with which Barnard found it. He described it as "Small, very difficult, with a star 10 close south" (the star is there). This is apparently from a letter to Dreyer as the observation does not appear in the Sidereal Messenger where Barnard published other of his early nebular discoveries. ===== NGC 2226. See NGC 2225. ===== NGC 2234 is described by both WH and JH as a very large cluster, at least half a degree across. I find three concentrations of stars in the area, the first at 06 25.4 +16 42, the second at 06 26.5 +16 45, and the third at 06 27.4 +16 30. Perhaps the Herschels' observations refer to all three. As with so many of the poor, scattered "clusters" found by them, telescopic observations will be needed for conformation. ===== NGC 2237, 2238, and 2246 are all parts of the large annular HII region often called the Rosette. Embedded in the middle of the nebula is a bright cluster of young stars, NGC 2239 = NGC 2244 (which see) discovered by WH, and observed again by JH. Albert Marth is apparently the first to see any part of the nebulosity (NGC 2238, which see), though Lewis Swift was the first to call attention to its great size. Barnard ran across the nebula independently in 1883 while sweeping for comets, and his observations inspired Swift to finally publish a note about it in 1884. Scanning the area again in 1886, Swift found part of the eastern side of the nebula (NGC 2246, which see), but it was not until Barnard began his photographic work at Lick in the early 1890s that the full extent of the nebula became known. The position for NGC 2237 given by Swift in his second list of nebulae actually comes from Barnard, though it is about 45 seconds of time west of the center of gravity of the western part of the Rosette to which it refers. Barnard's description is accurate, however, and there is no question as to which part of the nebulosity he saw. ===== NGC 2238 is a small patch of somewhat brighter nebulosity in the much larger Rosette Nebula. It was found by Marth in 1864 with Lasalle's 48-inch reflector, which probably accounts for Marth's ability to see the faint star embedded in the knot. See NGC 2237 and NGC 2239 for more on the Rosette. ===== NGC 2239 = NGC 2244, the bright young cluster in the center of the HII region called the Rosette (see the discussion under NGC 2237), was found by WH. JH recovered it 30 years later during his northern sweeps from Slough, though he made an error of 1 minute of time in the position. Neither noticed the nebulosity around the cluster; that remained for Marth, Swift, and Barnard to bring to our attention. ===== NGC 2242. See IC 2170. ===== NGC 2244 = NGC 2239, which see. ===== NGC 2245 is not identical to IC 447, in spite of what Barnard has to say in the caption to Plate 28 of Vol. 11 of the Lick Publications. He has misidentified IC 447 as NGC 2245; the NGC object is northeast of the larger more diffuse IC 447 at 41 mm from the right edge and 87 mm from the top of the plate. For comparison, I measure IC 447 to be at 31 mm and 94 mm (Barnard has 30 and 94). He does identify IC 446 correctly. See IC 446 = IC 2167 and IC 447 = IC 2169 for stories of their own. ===== NGC 2246 is a brighter patch of nebulosity in the eastern side of the Rosette first seen by Swift in 1886; see NGC 2237 and NGC 2239 for more on the discovery of this remarkable object. ===== NGC 2248. This asterism of nine stars was recorded in the Markree Catalogue where it remained essentially unnoticed until Auwers reobserved it in the late 1850s. He included it in his 1862 list of nebulae and clusters found by observers other than the Herschels, and JH picked it up there for the GC. The original position is good. ===== NGC 2250 is placed 1 minute of time too far west in RNGC and in the Alter and Ruprecht star cluster catalogue. JH recorded as the position that of the 8th magnitude star we now call SAO 133414, though that is on the eastern side of the cluster. The approximate center is about three arcminutes west-southwest of that star. ===== NGC 2253 can't be found. There is nothing at W. Herschel's position (06 36.8 +66 53, 1950), nor is there much to suggest a systematic error in the positions of the other objects found that night (NGC 2347 = III 746, though see this for some confusion; and NGC 2403 = V 44). Herschel's description -- "A vF patch or S cl of eS st(ars)" -- as well as the fact that he included this object in his class VII (number 54) suggests that we should be looking for a small, tight group of faint stars. There is a scattered group of (10 or 15 stars of magnitudes 14 to 16) at 06 37.4 +66 22 (1950), but it is not a "patch" by any stretch of the definition of that word. Herschel's description might just as well fit UGC 3511 (06 38 45.8 +65 15 22, 1950), a rather patchy late-type spiral galaxy, but the position is off by random amounts in both coordinates. Similarly, the CGCG object at 06 38.2 +65 43 (1950) is probably not WH's object. Since there are no reasonable solutions that we can easily see, we'll just have to let NGC 2253 be "Not found" for the time being. ===== NGC 2254. The NGC RA for this cluster is 10 seconds of time too far west. While that may be an error in reduction of WH's or JH's observations, it could also simply be a statistical fluke. ===== NGC 2261 is often called "Hubble's Variable Nebula" as its variability was indeed first noticed by Hubble during his years at Yerkes Observatory. The nebula was discovered, though, by WH in 1783, and is the second of his new class of "planetary" nebulae. We know now that the nebulosity is actually enveloping a very young double star system, R Monocerotis. The star's variability was first noted by Schmidt (AN 55, 91, 1861). The variability of the nebula is probably the result of circumstellar clouds close to the stars casting shadows on the surrounding nebulosity. NGC 1554/5 (which see) around T Tauri is another example. ===== NGC 2265 appears to be no more than a random grouping of stars. On the POSS, it is an elongated group of 12th to 14th magnitude stars about 10 x 5 arcmin in size, centered about three arcmin southwest of JH's position. ===== NGC 2270. Found by WH who called it "A cluster of very scattered stars, considerably rich and of very great extent," this appears on the POSS as an irregularly scattered grouping of about 50 stars centered about 2 arcmin north of the NGC position. About 12 arcmin north and 4 arcmin west is another similar group of stars. Could this second group be the reason WH noted the "very great extent" of the object? ===== NGC 2274 and NGC 2275. The UGC and MCG identifications of this close pair are opposite one another. This has happened in at least two other cases: NGC 980 and 982 where there is indeed an error in the NGC declination for one object, and NGC 5216 and 5218 where there is only a small error in John Herschel's 1833 list and the reversal of the identifications in MCG. The NGC, however, is correct in this second case (see the discussions of these objects for the details). In the case of N2274 and N2275, there is indeed an error in the NGC, but it is such a trivial one that I doubt that it led to the MCG reversal (it is indeed MCG that is incorrect here): the numbers from William Herschel's catalogue are reversed. JH got them right in his 1833 catalogue (and the GC) when he listed them under h406 = H II 614 and h407 = H II 615. Dreyer, too, got them right when he republished William's Scientific Papers in 1912, but did not mention the earlier mistake in his errata list of that year. In the end, it is clear that NGC 2274 is the southern and very slightly preceding of the two. The MCG identifications should be switched. ===== NGC 2275. See NGC 2274. ===== NGC 2277 is an asterism of five faint stars. It was found by d'A as he reobserved the interesting area containing NGC 2274, 2275, and the NGC 2290 group. Apparently observing on a poor night, or anxious to increase the number of nebulae in the area, he also found three other asterisms here (NGC 2278, 2284, and 2285, which see). ===== NGC 2278 is a double star found by d'A. Bigourdan reobserved it, and found a companion asterism nearby, NGC 2279 (which see). See also NGC 2277. ===== NGC 2279 is a triple star (one star is very faint) found by Bigourdan while he was measuring the previously discovered nebulae and asterisms in the area. See NGC 2277 for more. ===== NGC 2282 = IC 2172, which see. ===== NGC 2283 may also be IC 2171, which see. ===== NGC 2284 is an asterism, probably comprised of the four stars noted in the table, but perhaps the triple 2 arcmin southeast. It was found by d'A in the area between the NGC 2274 group and the NGC 2290 group. See also N2277 and N2285. ===== NGC 2285 is a double star. See NGC 2277 and NGC 2285. ===== NGC 2290 is the brightest of a group of galaxies. There are several asterisms in the area, too (see e.g. NGC 2277, 2278, 2284, and 2285). ===== NGC 2296 = IC 452, which see. This, by the way, is a Galactic diffuse nebula, not a galaxy. ===== NGC 2299 is probably the same cluster as NGC 2302. JH saw the cluster we now call N2299 only once, and noted its position as uncertain in both coordinates. his description reads, "A coarse cluster, not very rich; 30 or 40 stars; probably only an outlying portion of VIII 39"; this could easily match N2302. His three accordant observations of N2302 are all in other sweeps. Had the two clusters been seen on the same night, I would not have entertained thoughts about equating the objects. As is, however, I think it's likely that the two numbers refer to the same object. ===== NGC 2302 probably = NGC 2299, which see. ===== NGC 2306 is probably a rich portion of the Milky Way. Neither WH nor JH seemed mightily impressed with it. JH in particular thought it simply a concentration of stars rather than a true cluster. Examining the POSS1, I thought it might be identical to NGC 2309 which is 1.5 minutes of time to the east. However, JH saw both objects in the same three sweeps: his concurrent observations rule out an equality. The "object" I've chosen as N2306 appears on the POSS1 as an elongated cloud of stars, magnitudes 10-13, roughly 20 arcmin by 10 arcmin, with the long axis in position angle 70 deg. The position in the table is just an arcmin southwest of JH's position, adopted for GC and NGC. ===== NGC 2319. This object has a curious history. Before I get into that, however, I should say that I've finally assigned the number to h 423 which JH describes as a "Linear cluster of stars, forming a bent line nearly 15 arcmin long, terminated on the following side by a star 8 ..." He calls the cluster "VIII 1," though it is not (more below). The position I've assigned (06 57 55, +03 06.8; 1950) is for the mid-point of the chain, rather than that of JH's 8th magnitude star (he gives 06 58 31, +03 07.9 -- also 1950 -- less than an arcmin from the true position), so the RA is well off JH's, though the object is clearly the one that he saw. For the GC, he used his own position for the object rather than his father's (for reasons apparent below), and Dreyer did the same for NGC. This leads us unambiguously to JH's "bent line" as NGC 2319. Curiously and perhaps unfortunately, both JH in GC and Dreyer in NGC also assigned an unusual WH number to the object: VIII 1B. There is no VIII 1A, and VIII 1B turns out to have nothing to do with VIII 1 (which is NGC 2509) except that it follows the first entry chronologically in WH's list of scattered clusters. So, to the history. Dreyer has a short note in the NGC, beginning with JH's note in the GC: "Entered by CH as VIII 1B, with a remark `not in print.' -- JH." Dreyer continues, "It must be a very poor cluster; at any rate, Auwers could not find anything like a cluster in this place." Dreyer inserts VIII 1B in his 1912 edition of WH's first catalogue with an extensive note giving some of the details of WH's Sweep 48 on 18 December 1783. In short, WH's observation puts the cluster around 1950.0 RA = 06 45.3, and between +02 06 and +03 21. He describes it as "A cluster of very small stars, not rich." This is obviously too far off JH's position to be the same object, so I am wondering how JH arrived at the identity. In any case, there is no obvious cluster matching both WH's position and his description. Two objects partially match, however: Collinder 115 (at 06 44 03, +01 49.4 for 1950) matches the description, but is well off in position. A scattered group of 9th to 12th magnitude stars at 06 44 52, +03 08.0 comes closer to the position, but the stars -- particularly the 9th magnitude star near the center -- are too bright to appear "very small" to WH. I see nothing else that could be WH's cluster. In the end, H VIII 1B remains a footnote, unidentified and probably unidentifiable (though a careful scrutiny of the Herschel Archive might turn up more information than Dreyer found -- but that's unlikely in my opinion). It's connection with NGC 2319 is a mistake by JH and Dreyer, and it has no other NGC number. ===== NGC 2323 (M 50) has an apparent core-halo structure on the sky survey prints/ films and DSS. The overall diameter is roughly 30 arcmin by 25 arcmin, with the core being just 10.5 by 8.0 arcmin. Most previous catalogues put the diameter at about 15 arcmin, but I have no idea now whether that is just an eyeball estimate, or is based on photometric and proper motion studies. The diameters I measured are obviously just estimates. I also put the position slightly southeast of Brian Skiff's or the one from him adopted by Brent Archinal and Steve Hynes in "Star Clusters". The core- halo structure is well-shown in the DSS image reproduced in "Star Clusters" as Figure 4.70. ===== NGC 2326. This was originally found by William Herschel who describes it as "F, pL, iF, mbM. South-following a triangle of small [faint] stars." JH looked at it a quarter of a century later and noted: "eF, R, pslbM; has a small group of stars immediately preceding like the letter Y." The J2000.0 position from the Bologna group is 07 08 11.1, +50 40 53 which is in the right direction from the NGC 2000.0 position to agree with the position measured by Glen Deen in the course of his work on MicroSky. The group of stars just west, shaped like the letter Y, clinches the identification, even if the NGC position (from the Herschels) is not too good. ===== NGC 2327 is a compact HII region, or part of one, in the large, sinuous nebula found by Max Wolf south of IC 2177, which see. ===== NGC 2330 and NGC 2334. Malcolm has not been happy with my assignments of NGC 2330 and NGC 2334 to IC 457 and IC 465. After going over all of the extant historical evidence once again, I'm not happy, either. But I'm not sure what to do about it. Here's the story. WH swept over this field twice, finding -- so he thought -- two nebulae, II 736 (on 9 Feb 1788) and II 862 (on 28 Dec 1790). His positions reduce to 07 07 21, +50 14.2 and 07 07 03, +50 14.4 (both for B1950.0). Since NGC 2332 is well over a minute of time preceding either of these, I think that both observations refer to NGC 2340. That galaxy is, in any case, the brightest in the group. WH's descriptions are consistent with his observations refering to the same galaxy. When JH swept up the field about 35 years later, he picked up NGC 2340 twice and NGC 2332 once. His positions and descriptions match the two galaxies well, so there is no reason to doubt that he actually did see both. After another 25 year gap, Lord Rosse turned his 72-inch "Leviathan" on the field. Unfortunately, the three sketches he made during his first two observations in January of 1851 did not appear in his 1861 monograph. He had only a short note under his entry for h 430, "Several knots around; 430 is E np, sf" (the directions should read "sp, nf"). So, when JH assembled the GC, he had only this scanty note on which to base the entry for GC 1492. Consequently, the position for GC 1492 is very rough (06 58+-, 39 36+-; RA and NPD for 1860), and the description reads only "Several near h 430 (?426, 433, & 1 nov[a])." When Dreyer was preparing LdR's observations for publication, he transcribed the details missing from the 1861 monograph, giving us the first two night's notes and sketches. Unfortunately, the arrows in the sketches are pointing in the wrong directions, and (as I noted) north and south are reversed in the notes for the first night's observations of NGC 2332 = h 430. I think that the first two sketches must come from only the first night: one shows NGC 2332 and a new nebula, with the second showing NGC 2340 and another nova. I also think that these are the objects which Dreyer intended to include in the NGC. This is the reason that I earlier adopted the NGC numbers 2330 and 2334 for them, in spite of the large differences in position from the NGC positions (from Bigourdan's observations; more on these below). The notes for LdR's second night refer to five novae, as well as the two known objects. A third sketch -- apparently from that night -- shows a total of nine nebulae. A third observation in 1863 refers to only six of these, with Dreyer adding the comment, "Zeta, iota, and theta not noticed this night." This is understandable as LdR says "A fog prevented these being well seen." In any event, Dreyer clearly had evidence for nine nebulae in the field, yet chose to include NGC numbers for only four. Perhaps he did this because he thought he had good positions for only those four -- two from JH via the GC, and two from Bigourdan for two of the "novae." However, given the confusion of the directions in the sketches and the observing notes, Dreyer was unable to sort out the field satisfactorily. So, he put question marks on LdR's initials under the numbers 2330 and 2334, adopting Bigourdan's positions published in his (Bigourdan's) first list. Dreyer could have inserted numbers for the remaining five nebulae, trusting to future observers to provide good positions, but unfortunately, did not. It is here that Bigourdan's complete observations could have provided positions for most of LdR's novae, had he (Bigourdan) chosen to publish them before the NGC appeared. For, on two nights in November of 1885, Bigourdan measured eight novae of his own, including six real nebulae, in addition to the two known nebulae. Unfortunately, he chose to publish only two of his novae. By startlingly bad luck, the two he did publish are stars. The six real galaxies remain buried in his massive tables of observational details and did not appear until 1907 in the Observations of Paris Observatory. Consequently, Dreyer put the two stars, with Bigourdan's positions and descriptions, into the NGC. While his clear intent was to include two of LdR's nebulae, he just as clearly -- with Bigourdan's unknowing assistance -- botched the job. So, what do we do with the two errant NGC numbers? If we assign them to the stars which Bigourdan's positions and descriptions point at, we do Dreyer's intentions (and JH's in the GC as well) a misservice. If, on the other hand, we assign them to the two novae that LdR found in 1851 (IC 457 and IC 465), then we incur Malcolm's wrath and my own furrowed brow. My solution is to adopt both options with lots of question marks, knowing full well that neither is satisfactory. Dreyer has simply not left us enough information to make any clear choice. As a footnote, I should mention that Heinrich Kobold also stumbled across this problem in 1893. He published a short note in AN 3184 with good positions for NGC 2332, 2340, and nine other nebulae which he assumed included those found by Lord Rosse. However, he could not find Bigourdan's two published novae (the ones with NGC numbers). Dreyer put all of Kobold's novae into the first IC, and included a note reporting Kobold's negative observations of the two NGC numbers. Finally, a footnote to the footnote: Kobold published his complete observations in the Strassburg Annalen in 1909. There, he has two observations of I459, but has reversed the signs on the offsets for one of them. He apparently discovered this before he published his short announcement in AN, so he did not publish a non-existent object (one object, IC 462, is a star, however). Since his monograph was published long after the observations, and long after he found the error, it's puzzling that he should let the mistake stand. The fact that the wrong signs are not just typos is shown by his including the second observation as if it were for another object. Also, his summary list of reduced positions includes only the IC objects (with the correct number of observations for each), so the decision to publish the incorrect observations is doubly puzzling. I certainly wouldn't have done it that way! ===== NGC 2331 is a large, scattered cluster of pretty bright stars. There is a concentration of several stars on the southeast edge that attracted JH's attention enough that he took it as the position for the whole object. Thus, the position in the main table is about 8 arcmin northwest of the NGC place, copied directly from GC and JH. A curious footnote to this object is in the "Other Observers" column in the NGC: "Flamsteed." I do not know yet why Dreyer credited Flamsteed with the discovery -- there is no mention of the object in Kenneth Glyn Jones's fine book, "The Search for the Nebulae." According to Glyn Jones, Flamsteed did find several other objects in the area, including M41 and NGC 2244. But this cluster is missing from his catalogue and atlas. ===== NGC 2332. See NGC 2330. ===== NGC 2334. See NGC 2330. ===== NGC 2338 is probably the cluster about 50 seconds following and 5.5 arcmin south of JH's place. Brian Skiff and I independently found the cluster looking for N2338; it matches JH's description "Very loose and straggling cluster" pretty well, and is as good a candidate as any. ===== NGC 2340. See NGC 2330. ===== NGC 2343. See NGC 2351. ===== NGC 2347 and IC 2179. On 1 Nov 1788, William Herschel found a "vF, S, R, lbM" nebula 01h 04m 05s following, 48' south of 36 Camelopardalis (the observation is from Dreyer's 1912 collection of Herschel's papers). This position reduces to 07 11 54, +65 06 using the SAO position of 36 Cam (proper motion changes its precessed position by about 5 arcsec between 1788 and 1950, a negligible amount considering the mean errors of a few arcmin in WH's positions). The GC/NGC position precesses to 07 11 31, +64 54. Since no other reference for the position is given, I suspect that JH must have used a later unpublished observation from his father's records. The NGC position falls about 6 arcmin north-following a 13th magnitude spiral galaxy (at 07 11 15.9, +64 47 57) which is usually taken as NGC 2347. However, 9 arcmin south-preceding the NGC position is a smaller, but equally bright -- therefore, higher surface brightness -- S0 galaxy. This was found by Bigourdan while he was searching the area of N2347, and is in IC2 as IC 2179. The position there is within 2 arcmin of the correct position (07 10 42.6, +65 00 49). Is this possibly the object that WH saw? Bigourdan apparently thought so, since he assigned the number "NGC 2347" to his observations of this smaller galaxy. However, he lists SA0 14129 as his comparison star. Using the 1950 position for this, we find a position for the galaxy of 07 11 26.5, +64 52 11, quite close to the NGC position for N2347. This certainly explains Bigourdan's choice of this object for N2347. If we look at this position on the sky, however, we find nothing at all. But applying Bigourdan's offsets to the position for BD +65 560 = GSC 4119-00435 (a star about a magnitude fainter, but still bright), we land exactly on IC 2179. But Bigourdan's observations, referred to SAO 14129, of what he calls "IC 2179," point exactly to the spiral usually called N2347. Thus, it's clear that not only has Bigourdan misidentified his comparison star for I2179, he has also switched the two catalogue numbers. But where did the correct IC position come from? Since Bigourdan published his "new" nebulae in several short lists in Comptes Rendus, Dreyer most likely took the position from there. However, in his collected lists of "novae" in the introduction to his observations, Bigourdan prints the incorrect position given in the observations themselves. At the moment, I don't see a reasonable answer to the problem. Until more information surfaces, we will retain the usual identifications for the two galaxies: NGC 2347 is the south-following spiral, and IC 2179 is the north-preceding lenticular. See also the additional discussion under IC 2179. ===== NGC 2349. This cluster was found by CH in 1783, and later catalogued by WH as VII 27. Their object, centered near 07 08 24, -08 30.6 (less than 30 arcsec from where they put it), is easily identified by the "extending branch towards the south-preceding." JH, however, called it a "poor straggling cluster," and took its position as that of a double star some 50 seconds west of the object observed by his father and his aunt. He adopted this position for GC, and Dreyer followed suit for the NGC. He must not have seen the same cluster as his father and aunt, however -- the positions and descriptions disagree too much. ===== NGC 2351. There is nothing in JH's position, but one degree north is a group of three bright and several faint stars that could be the object he saw. I'm frankly not too happy with this idea, but there isn't much else going. Other possibilities: this object may be a duplicated observation of NGC 2343 or NGC 2353, though neither one has a position with an obvious digit change that might point to NGC 2351. ===== NGC 2353. See NGC 2351. ===== NGC 2355. See NGC 2356. ===== NGC 2356 is most likely NGC 2355 with a 10 arcmin error in declination. There is no other group of stars in the area that fits WH's description "A pretty rich and compressed cluster of stars" as well. JH did not see NGC 2356, but found NGC 2355 easily. Note, too, that WH's position for N2355 is about 1m 40s too far west; Dreyer discusses the circumstances of WH's observation of N2355 a bit more in his 1912 edition of WH's papers. ===== NGC 2358. Seen only once by WH, this may be the large (20 arcmin by 15 arcmin) scattering of stars around 07 14 42, -17 01.6. Alternatively, it could be the richest part of this group, on to the southeast at 07 14 59, -17 04.2, though this is further from WH's position. Since we don't have much to go on here, I've taken the former position for the larger group as the most likely. ===== NGC 2359. See NGC 2361. ===== NGC 2361 is a knot in NGC 2359. JH's description and sketch from his Cape Observations is very appropriate for the larger object. Bigourdan's descriptions of N2361 make it clear that he was seeing only a small part of JH's object. Dreyer's IC1 note suggesting that N2361 is a reobservation of N2359, suggests that he had not seen Bigourdan's observations. ===== NGC 2363 and NGC 2366. Well, folks, it's bad news for those of us who have always identified NGC 2363 as the giant HII region in the low surface brightness irregular galaxy NGC 2366. WH's original description clearly refers to the HII region as the principal object with the bit of fuzz to the north as an incidental appendage. This view was further solidified by Ralph Copeland, observing with Lord Rosse's 72-inch reflector. Copeland identified the HII region as the center of an greatly extended object, stretching 9 or 10 arcmin to the northeast. He lists micrometric measurements of seven different objects in the surrounding area, and all are clearly referred to the HII region. Here is a list of his measurements, along with mine (made from the POSS1 blue print): Copeland Corwin Note Object P.A. Dist. P.A. Dist. * 9.5 6.3 214.9 7.5 211 * 10 337.9 191.9 335 193 * 10 340.8 235.8 339 236 * 8 351.0 396.6 351.5 400 Dif neb 265.9 71.4 274 70.5 Copeland quadrant error? Neb * 318.0 77.6 318 75.2 Star sup on F ext of galaxy "Tail" 30.9 [9-10min] 31 8min+- Main body of the galaxy So, the historical record is unmistakeable: NGC 2366 is the HII region. We can, of course, also include the rest of the galaxy under this number, since it was certainly seen. For the sake of the modern catalogues, this is also certainly the best thing to do. But what then is NGC 2363? One of Copeland's micrometric measures above -- for the "Diffused nebulosity preceding" -- is the one that Dreyer put into the NGC with the note "III 748 s[outh] f[ollowing]." This, combined with Copeland's measurement which Dreyer used, clearly points to the smaller object that we now call UGC 03847 = MCG +12-07-039 (N2366 is U3851) -- it is NGC 2363, not the HII region. I have usually taken this object to be a detached star cloud of N2366, but Steve Odewahn has shown through his detailed study of the velocity fields of the objects that it is indeed a separate galaxy interacting with N2366. So, we have two galaxies here, along with two NGC numbers clearly attached to each one. We shall just have to get used to calling the HII region "Markarian 71" (or one of its other names) since it is not N2363 as we've thought all these years. There is still one other nebulous object seen by Copeland in the area. This is the "Nebulous star or nebulous knot" which is listed in the table above. Why didn't Dreyer include it in the NGC, too? Other objects with just that sort of description were included. While this is an unanswerable question, it's possible that Dreyer had access to other notes that were not published. Or, since he and Copeland were colleagues at the time, the two of them may well have decided that the object was a star. The object is indeed a star superposed on a faint extension of NGC 2363. There may also be a distant background galaxy adding to the appearance of nebulosity -- see the lovely 200-inch photographs in the Revised Shapley Ames Catalogue (page 113) and in the Carnegie Atlas (Panel 327). ===== NGC 2366. See NGC 2363. ===== NGC 2364 is a curious object, probably a simple asterism of unrelated stars. It is composed of two n-s lines of half a dozen stars each, with a void between the lines. The two star streams are slightly tilted with respect to each other, and there is another star at the apparent apex to the north. There is a straggling line of similarly bright stars running east just to the south of the eastern stream. There is no question about the identification as JH's position and description are perfect for the object. Most of the stars may be bright enough that we can check their proper motions, too, in Tycho-2 or in UCACS. That is left as an exercise for the curious. Curiously, RNGC has this as "Not found" even though it is very clear on the DSS and, presumeably, the Palomar Sky Survey prints. I noted the NGC position and description correct when I scanned through for ESGC in the mid-80s, and Brian Skiff says "*ism, but real object". ===== NGC 2378 is a double star precisely identified by Stephan's micrometric position, and his description, "Two stars, very faint and very close which, occasionally seem to be enveloped in a nearly imperceptible nebulosity." ===== NGC 2380 = NGC 2382, which see. ===== NGC 2382 = NGC 2380. JH found this nebula in two different sweeps just four days apart (1 and 5 February 1837), but catalogued it as two different objects. Dreyer called attention to JH's approximate position for N2382 in the IC2 notes where he also gave Howe's micrometric position for the galaxy. Curiously, neither noted the identity with N2380, though Howe had mentioned in an earlier Monthly Notices article (Vol. 58, p. 515, 1898) the relative ease with which he saw that object. It was there that he also noted unsuccessful searches on two nights for N2382. In his second note about the galaxy two years later (MN 61, 29, 1900), Howe notes the declination error of 10 arcmin, and the RA error of 18 seconds. But it was left to Andris and me to note the equality of the two NGC numbers in the 1980s when we published our southern catalogues. Finally, I should note that JH has a correction on the errata page of his CGH volume to the RA minutes of NGC 2380 where it appears there as h3079. ===== NGC 2386 is a triple star near NGC 2388 and NGC 2389. Like many other asterisms found by Lord Rosse and his observers, it was taken to be part of a group of nebulae, probably on a night of poor seeing. ===== NGC 2388. See NGC 2386 and NGC 2390. ===== NGC 2389. See NGC 2386 and NGC 2390. ===== NGC 2390 and NGC 2391 are both stars near NGC 2388 and NGC 2389. Both are shown in Ball's diagram of 10 Dec 1866, and he has a micrometric measurement of NGC 2390. ===== NGC 2391 is a star. See NGC 2390 for a bit more. ===== NGC 2398, found by Stephan, is the brightest of three galaxies. Javelle saw one of the other two, but his note is not clear on which one. Since he gave no other details, the second object does not have an IC number. ===== NGC 2399 and NGC 2400 are a pair of triple stars found by George Bond with the Harvard refractor on 26 Feb 1853. Bond gave only one position (closer to N2399), but Schultz later measured both. D'Arrest has the two 1 minute of time further east, but Bond and Schultz are correct. ===== NGC 2400 is a triple star. See NGC 2399. ===== NGC 2402. Though both WH and JH have this as a single nebula with a single star involved, there are actually two galaxies and two stars here. The south- western galaxy is the brighter, but has the fainter star superposed, while the fainter northeastern galaxy has the brighter star. I suspect that the Herschels saw the entire group of four objects as a nebulous blur with the brighter star occasionally glimmering through. ===== NGC 2403. See NGC 2253 and NGC 2404. ===== NGC 2404 is the brightest superassociation in NGC 2403. The NGC position, however, is wrong, as is the position in Bigourdan's first Comptes Rendus paper. The correct position appears twice in his lists of new nebulae in his massive "Observations ...," and the offsets he gives also reduce to the correct position. My earlier incorrect identification of this as a star is based on the NGC position. ===== NGC 2408 is probably a field irregularity. On DSS, I see a scatterering of 20-30 stars, roughly 10th - 12th magnitude, covering an area of about 25 by 20 arcmin. It is centered just west of the brightest star in the ensemble; this seems to be the star that JH took for his position. ===== NGC 2412 is a star found by J.G. Lohse. I suspect its companion 10 arcsec south, mentioned by Lohse, has contributed to an appearance of nebulosity at the eyepiece. The other star Lohse mentions in his notes is SAO 115663, a "star 8 following 59 seconds, 1.5 arcmin south." Lohse's position for N2412 is also good. ===== NGC 2422 is probably also M47 = NGC 2478, which see. ===== NGC 2428. See NGC 2430. ===== NGC 2430 may be the large sparce group of relatively faint stars centered about 5 arcmin north-east of WH's position. There is a concentration within this group centered just 6 seconds following his position, but it is rather small (8 x 4 arcmin) for a cluster described as "very large." The larger grouping is 14 x 11 arcmin across, so that is the one I've tentatively taken. Another possibility is OCL 606 1.7 minutes following, and 5 arcmin north, of WH's position. The 1.7 minutes is not an easy mistake to make, however, so I'm doubtful about this. But that cluster does match WH's description, so it remains a possibility. NGC 2428 was found in the same sweep just 9 seconds preceding and 10 arcmin south of NGC 2430. Had the two been found in different sweeps, I would have confidently declared them to be identical. NGC 2428 is clearly a cluster that matches WH's description (and his position), and I could easily imagine that it could be stumbled across independently on different nights. However, having been found so close together, apparently within a few minutes of each other, the two objects that WH recorded are almost certainly different objects. ===== NGC 2431 is probably also NGC 2436, which see. ===== NGC 2433 is a triple star at JH's position. The 15th magnitude field star that he noticed to the northwest is at 07 39 57.13, +09 23 17.4 (B1950.0, measured on DSS as are the rest of the positions in this note). Dreyer has an NGC note that questions whether JH or d'A has the correct RA, both having just a single observation of the object. Checking at d'A's position shows a double star: 07 39 40.64, +09 23 47.6 and 07 39 41.85, +09 23 59.8. D'A also notes a 12th magnitude star to the southwest: 07 39 36.75, +09 22 32.5 (blended into a single image on DSS). He was puzzled by the discrepancy with JH, suggesting that JH's position was 19 seconds off. I've of course adopted JH's triple star as the correct object. (LEDA makes NGC 2433 a faint galaxy on to the northeast, but this is clearly wrong.) ===== NGC 2436 is probably NGC 2431. JH's RA is exactly 1.0 min larger, and his Dec exactly 1 deg smaller than those for NGC 2431. The description matches the bright core of the galaxy, so I am pretty sure that the identity of the two numbers is correct. Nevertheless, there is a triple star about 3 arcmin southwest of JH's uncorrected position (07 41 57.4, +52 09 36; B1950.0). This might be the object he saw -- but I doubt it. The errors leading to NGC 2431 are too exact to ignore. ===== NGC 2442 and NGC 2443 are the southwest and northeast parts of a large, bright galaxy observed four times by JH. The last three times, he described it as a single large nebula, and measured a position for it that agrees very well with the modern position. His first observation, however, makes it "A double nebula, vF, vL, PA of centers = 40 deg, diameters 4' and 3' running together, and having a star 13 mag at their junction." This is the interpretation that he adopted for the GC, and that Dreyer used in the NGC. The "double star" that JH noted during one observation is the nucleus and a superposed star (or a compact HII region). In the main table, I've given the position of the nucleus under both numbers, and have also given positions for the approximate centers of the two halves of the galaxy. ===== NGC 2443. See NGC 2442. ===== NGC 2456. See NGC 2457. ===== NGC 2457. The identity of this galaxy is not in doubt: Copeland gives a micrometric offset from NGC 2456 for it, and it is just where he claims to have seen it. What is interesting is his comment in the description, "About 3' north of the nova, there seemed to be another vF nebula. Telescope now at the limit of its range." There is in fact a fainter galaxy just three arcmin to the north of NGC 2457. Dreyer could well have included this in the NGC, but chose not to, apparently because of Copeland's apparent uncertainty about its existence. This makes at least three nebulae found by Copeland that are not in NGC -- interesting since Copeland was a friend and colleague of Dreyer's. ===== NGC 2458. See NGC 2469. ===== NGC 2461 is a star. See the discussion under NGC 2469. ===== NGC 2462. See NGC 2469. ===== NGC 2463. See NGC 2469. ===== NGC 2464 is a triple star. See the discussion under NGC 2469. ===== NGC 2465 is a star. See the discussion under NGC 2469. ===== NGC 2469 group. Two objects here were seen by the Herschels: NGC 2463 (JH) and NGC 2469 (WH and JH). The identity of these two is certain since John Herschel's positions are good. Lord Rosse saw, but did not measure them. He has only a note: "Great many knots, reckoned 10 nearly in a line pf." So, Herschel added eight other GC numbers for the additional objects even though no positions were available for them. Dreyer followed Herschel's lead explicitly with 10 NGC numbers for all the objects. Bigourdan measured eight of the 10 objects in 1886, so Dreyer was able to adopt Bigourdan's positions and identifications for six of the non-Herschel objects: NGC 2458, 2461, 2462, 2464, 2465, and 2471. Bigourdan returned to the field in 1895 and 1900, measuring three other objects, one of which he mistook for NGC 2458, and another which became IC 2210. A third was not included in any of Dreyer's catalogues, and did not even receive a number in any of Bigourdan's lists of "novae." He did not observe NGC 2472 or 2473 -- the final two of Lord Rosse's 10 -- so they have only approximate positions in the NGC. The Palomar Sky Survey shows only seven galaxies here, one faint and small enough, and well enough away from the others, that it may not have been seen by Lord Rosse. It was certainly not seen by Bigourdan, who in fact saw only four of the galaxies (his first observation of N2458, N2462, 63, and 69). Five other of his objects are asterisms -- single stars (N2461, 65), doubles (N2471, I2210), or a triple (N2464). The two remaining nebulae in Bigourdan's list (his second observation of N2458 and the unnumbered "nova") are unidentifiable, with only very faint stars near -- but not at -- his positions. As I mentioned above, the chances are good that Lord Rosse only saw the six brightest of the galaxies (the others were probably stars as the rich field is at a fairly low Galactic latitude; it is not unusual to find stars among Lord Rosse's novae). Since Dreyer used Bigourdan's 1886 positions, four of the NGC numbers are assigned to galaxies, and four others are taken up by asterisms. There are thus two galaxies without NGC numbers -- and fortuitously, two NGC numbers (N2472 and N2473) without galaxies. Since N2472 has been used by the CGCG for one of the unnumbered galaxies, I suggest using N2473 for the other. The only unfortunate result is that this puts N2473 -- the last of the 10 numbers -- preceding all but one of the other objects (the exception is the very faint galaxy that Lord Rosse may not have seen): it is out of NGC order. It's clear that these two identifications are uncertain, even though they are logical given the facts we have. ===== NGC 2471 is a double star. See the discussion under NGC 2469. ===== NGC 2472. The identity is uncertain. See the discussion under NGC 2469. ===== NGC 2473. The identity is uncertain. See the discussion under NGC 2469. ===== NGC 2478 = M47 is probably identical to NGC 2422. NGC 2478 is a place-holder for M47 in the NGC; Dreyer simply copied JH's GC entry for the missing Messier cluster. He also noted Auwers's 4 minute RA difference for M47 as being a "clerical error", along with a reference ("V.J.S., Vol. I, p. 183" which I have not seen). Precious little to go on if one were starting here to find the NGC object. Glyn Jones has a story, though, in his book on the Messier objects (he repeats it briefly in "The Search for the Nebulae"). This story apparently comes from Owen Gingerich's article in the October 1960 issue of Sky and Telescope (page 196) on "The Missing Messier Objects". He claims Messier apparently switched the signs of his offsets from his comparison star, 2 Navis (now 2 Puppis), and cites articles or notes by Oswald Thomas in 1934 and T. F. Morris in 1959. This, however, doesn't hold up very well if we precess the three positions to 1771 when Messier found M47. 2 Pup ought to be about equidistant between the two positions for M47: Messier's as recorded in the NGC for N2478 (this is the same as that given by Gingerich in his article), and the real position for N2422 (WH found that in February 1785, coincidentally using the same comparison star. WH's offsets are 8m 55s preceding and 10 arcmin north of the star). The differences are 8m 54s and 9.7 arcmin (close to WH's) and 9m 18s, 41.0 arcmin, well off being identical, at least in absolute value, as they should be. So, while I can accept that Messier actually saw NGC 2422 and recorded it as his 47th object -- his description fits and the cluster is certainly in the right part of the sky -- I'm skeptical about the explanation that Morris, Gingerich, and Glyn Jones have set forth. ===== NGC 2491 and NGC 2496. Swift saw these as a pair oriented southwest- northeast, with his position for the brighter (N2496) being within 30 arcsec of a fairly bright galaxy with a faint star just preceding it. However, Swift puts the star to the east (following) where there is none. So, I'm going to suggest that his direction is wrong, but will still keep the galaxy as the one he saw. The other galaxy, though, is a problem. The object adopted by RNGC as N2491 (CGCG 031-007) is quite faint, and there are two others 10 arcmin north (CGCG 031-005 and 031-008) that would be easier to pick up: the former is considerably brighter and larger, while the latter has two stars just following that would enhance its visibility. These would have been well within Swift's 32 arcmin field, and should have been more apparent to him than the RNGC galaxy. In addition, Swift notes a "bright star near west." There is a 12th magnitude star about 2.5 arcmin to the northwest of CGCG 031-007; this might qualify as "bright" in a 16-inch refractor, but Swift usually reserved the word for stars of 10th magnitude or brighter. So, we have three galaxies to choose from: one matching Swift's position and (perhaps) his description, and two others that might be more easily seen. One option is that Swift has confused more than just his direction of the star near N2496: he confused all of the directions. This would make the orientation of the two nebulae northwest-southeast, and the bright star would be east, not west. This would make the star SAO 116199, which -- at 8th magnitude -- is indeed bright. The second is to simply accept Swift's positions as did RNGC and say that the descriptions are confused about the field stars. Adding to the confusion is Howe's observation of the field. He places N2496 near Swift's place, and notes the star preceding. But then he says, "... 2491, after careful scrutiny on a fine night, resolved itself into a few stars of mag. 14." The only object in the area matching this description is CGCG 031-008 -- but Howe makes no comment about the 10 arcmin declination error that must result. In the end, the identity of NGC 2496 is pretty sure, but that for NGC 2491 is uncertain enough in my mind to warrant some colons and question marks in the main table. Perhaps Swift was looking at a completely different pair of galaxies and simply got his positions wrong. If so, I haven't found the correct objects yet. ===== NGC 2494 = IC 487. Marth's position, accurately copied into the NGC, is 1 minute of time too small, an obvious digit error. Swift's position in the IC is not too bad, but is far enough off the NGC position that neither he nor Dreyer caught the identity. Herbert Howe missed it, too, and commented only on the position angle of the galaxy (he has it at 110 degrees, though I would put it closer to 95 degrees). Reinmuth, in his 1926 "Die Herschel Nebel," was, as far as I know now, the first to suggest the identity of the two objects. He describes the galaxy accurately, and provides an improved position for it, but also notes an "eFeS neb nnp 7.5'". The object most closely matching his distance from NGC 2494 is enough fainter than several other galaxies in the field that I do not believe that it is the object that Reinmuth found. ===== NGC 2496. See NGC 2491. ===== NGC 2509. See NGC 2319. ===== NGC 2515 is a double star. As with many of the other "nebulae" found at Harvard College Observatory during its early years in the 1850's and 1860's, there is no nebulosity associated with the stars. Poor seeing? Poor optics? Until someone examines the Observatory's early records in detail, we just won't know. In the meantime, however, the published position of NGC 2515 is very good, and the identity is certain. ===== NGC 2518 and NGC 2519 were "Two nebulae, F, L, R, gbM, delta RA = 42 seconds" found by J. G. Lohse. There is only one galaxy (UGC 04221) in the field about an arcmin from Lohse's position, but 39 seconds following it is a 14th magnitude star with 3 fainter stars in a triangle to the northwest. The asterism is about the size of the galaxy (35-40 arcsec across), and may be the object that Lohse saw. In any case, there is no other candidate object in the field. ===== NGC 2519. See NGC 2518. ===== NGC 2520 = NGC 2527. The puzzle here starts with the GC. JH has two observations of the cluster, one from Slough, the other from the Cape, both clearly of the same object. The RA for the Cape observation is out by 2.5 minutes of time, but JH nevertheless gives both earlier names (h488 and H VIII 30). Why then did he give the object two GC numbers? He has no notes in the GC, nor does Dreyer in NGC or in his collection of WH's papers. If anything, I would have expected him to adopt the Cape Observation since his earlier one has the note, "RA by working list," with the RA marked plus or minus. Whatever the case, there is certainly only one cluster, and both NGC numbers apply to it. ===== NGC 2524 and NGC 2528 are two galaxies found by Stephan in 1877. His positions are referred to BD +39 2062 = SAO 060607, so should be accurate within his measurement error of 2-3 arcsec. NGC 2524 is indeed where Stephan places it, but NGC 2528 is not south following as it should be if his position is correct. However, north preceding NGC 2524, there is a galaxy that fits Stephan's description perfectly. Looking at his measurements and plotting the galaxies and the comparison star, I found what Stephan must have done. The difference in position between the two galaxies is exactly equal to the difference in position between the star and NGC 2528. This means that Stephan actually measured NGC 2528 with respect to NGC 2524, not with respect to the star. He apparently forgot to make a note to that effect, so when he reduced his observations later, he assumed that both observations were referred to the star. Re-reducing his data taking this error into account gives positions in very close agreement with those in the GSC (aside from an offset in declination of about 15 arcsec because Stephan's declination for the comparison star is off by that amount). The PGC and RC3 have the correct identifications. ===== NGC 2528. See NGC 2524. ===== NGC 2529, 30, and 31. Herschel did indeed discover N2530, and this is the name that, as Steve Gottlieb suggests, should be used for the galaxy. The other two objects were found by Bigourdan very close to N2530. Though he examined the field four times, he saw his two new objects only once. On that one night, he estimated positions with respect to N2530: N2529 is 1' distant at position angle 220 deg, and N2531 is 1' distant at PA = 150 deg. There is nothing in either position on the PSS. He also measured a thirteenth magnitude star the same distance away from N2530 on two nights; it is just where he saw it in = 15 deg. On the second night, Bigourdan claimed to see stellar objects at the very limit of visibility where he placed N2529 and N2531 earlier, but he did not attempt to measure them. It's clear to me that the two do not exist, probably being those faint illusions that we all see now and then when we get tired or try too hard to push the limits of our optics. ===== NGC 2530. See NGC 2529. ===== NGC 2531. See NGC 2529. ===== NGC 2542 = 19 Puppis = SAO 153942 = ADS 6647. JH may have been misled by the faint companion to the brighter star. With a separation of only 2 arcsec, and a magnitude difference of 6.5, it would be very difficult to make out the fainter star except under extraordinarily fine conditions. ===== NGC 2543 = IC 2232. The galaxy was first seen by WH in Feb 1787, and was reobserved in Mar 1790. The two positions that he measured are not in particularly good agreement (08 09.6 +36 20 and 08 09.8 +36 35). JH picked it up once in Feb 1832. His position is 08 11 45, +36 24.6, also not in good agreement with either of his father's determinations. However, Sir John notes a "a coarse ** p points to it." This note is correct, and the "double star" is quite wide. The GC and NGC adopted sort of a mean of these three (08 10 43 +36 24.7) which was corrected by Dreyer in the IC 1 notes, following Spitaler (08 09 38 +36 24.7). Actually, Spitaler's micrometric position (measured in Dec 1891) reduces to 08 09 42.9 +36 24 07, using the GSC position for his comparison star, and ignoring its (unknown) proper motion. Javelle scanned the field in Feb 1896 and his position (for IC 2232) reduces to (again ignoring proper motion) 08 09 42.5 +36 24 12, agreeing well with Spitaler. Thus, there is no question that the two different numbers apply to the same object. This identity was first suggested as being the same as N2543 by Reinmuth in 1926, and every catalogue since has made the equality. The descriptions of the galaxy and the surrounding star field simply nail the lid, leaving no doubt about the equivalence of the two entries. ===== NGC 2574. See NGC 2589. ===== NGC 2582 = IC 2359. Here is a curious case. This is clearly noted as NGC 2582 in Wolf's first list, yet Dreyer still assigned it an IC number. There is no particular reason that he should have done this that I can see. The NGC position (from the two Herschels) agrees well with the GSC position, and with Wolf's position, and the descriptions are compatible. Oh, well -- these things happen. ===== NGC 2583 is a minute west of its nominal position. See NGC 2586 for more. ===== NGC 2584 is a minute west of its nominal position. See NGC 2586 for more. ===== NGC 2585 is a minute west of its nominal position. See NGC 2586 for more. ===== NGC 2586. This is a triple star. The galaxy with this label in RC3 (MCG -01-22-012) is near the nominal position, but N2586 is noted as the fourth of four nebulae. The other three (NGC 2583-5) are a minute west of Muller's position, but their relative positions are good. If N2586's relative position is similarly good, then there is little doubt that it is the triple star. ===== NGC 2589 is probably lost. There are no bright galaxies near Swift's position, though NGC 2574 (4 minutes preceding and 9 arcmin south) is a possibility. Given Swift's meager description, however -- "pF, pS, lE in meridian" -- this is little more than a guess. ===== NGC 2590 = IC 507, which see. ===== NGC 2597 is a double star. It is the preceding of two close "nebulae" that Marth found on New Year's night, 1864. The double is near Marth's place, as is his other object, NGC 2598, a galaxy. ===== NGC 2598. See NGC 2597. ===== NGC 2599. See NGC 2600. ===== NGC 2600, 2602, 2603, 2605, and 2606. There is a group of six galaxies here. Two (N2602 and N2606) of the three brightest were seen twice by JH, while he curiously missed the brightest, N2600 (LdR and Bigourdan picked this up). Of the three others seen by LdR, JH and Dreyer gave new GC and NGC numbers to only two, the other being taken as a star once, and being thought as one of the other two "novae" the second time. [There is also some confusion in LdR's 1861 PT paper, noted by JH in the GC Notes and by Dreyer in LdR's 1880 monograph, with NGC 2599 (= h507) 30 degrees south. Both JH and Dreyer come to the correct conclusion that this is a simple transcription error and that the correct numbers are h508 (= N2602) and h510 (= N2606).] JH's observations are relatively clear, though he does note a 10 second RA discrepancy between his first and second observations of N2602 (the second is more nearly correct). Also, his note "... np a star (about [PA =] 5 deg np)" should read "sp" instead of "np". As I've noted, his observations point at the second and third brightest in the group as being the two that he found. The first time LdR went over the group, he found three nebulae: 1850, Feb. 9. A fine object, 3 neb., one (N2600) B, another (N2606) f[ollowing] pB and E, the third (N2602) north and the last degree of faintness. [Dreyer appends the note about N2599.] LdR's second observation turned up four nebulae, and he provided a sketch: 1858, Mar. 11. 4 neb. found, alpha (N2603) is F, S, bM; beta (N2605) is vvF, gamma (N2602) F, S, lbM; delta is E and has a Nucl, a F * sf. alpha and gamma are about 5 arcmin dist. from one another, and beta and delta about the same dist. apart. Interestingly, he includes the faintest galaxy in the group in the sketch, but has it drawn as a star. Finally, a third observation yeilded only two nebulae: 1867, Mar. 5. 2 neb. seen nearly pf, p one (the unnumbered faintest galaxy in the group) eeF, f one (N2606) eF. Measures extremely difficult. Pos. 92 deg (2). Dist. 118 arcsec (1). In each case, the noted relative brightnesses and positions very clearly identify the objects that LdR and his observers are seeing. I find it informative that he turned up a different set of objects each night, pointing most likely to the importance of seeing, transparency, observer skill and fatigue, mirror reflectivity, and a host of other variables that determine the eventual outcome of any given observation. When Bigourdan went over the field, he found only the brightest three galaxies, N2600, N2602, and N2606, noting the others as simply "Non vue" (not seen). Making sense out of all of this is fairly straight-forward (though I swapped NGC 2602 and NGC 2605 in my first pass a few years ago; apologies to all). We simply adopt the NGC numbers for JH's two objects as given by Dreyer. JH's positions are not bad, either, though both he and Dreyer used a mean of the two discordant RAs for N2602. NGC 2600 is easy as its relatively good position comes from Bigourdan, and his comment about the two stars preceding is accurate. This leaves NGC 2603 and NGC 2605 to distribute among the three "novae" found by LdR. I've arbitrarily assigned these to the fourth and fifth brightest galaxies in the group (LdR's alpha and beta), leaving only the sixth and faintest without an NGC number. I've included this in the position table as "N2606 w comp". The final entry in the table, "N2606 e comp" is the "F * sf" that LdR notes in his 1858 observation. On the DSS, this looks like a close double, or perhaps another companion galaxy. ===== NGC 2602. See NGC 2600. ===== NGC 2603. See NGC 2600. ===== NGC 2605. See NGC 2600. ===== NGC 2606. See NGC 2600. ===== NGC 2617 is the brighter and western of two galaxies (it is MCG -01-22-026). The NGC position, from Stephan's careful micrometric measurements, is within a few arcseconds of being correct, so I'm puzzled by the occasional misidentification of this NGC number with the eastern galaxy (MCG -01-22-027). This is especially disconcerting since the eastern galaxy is considerably fainter as well. Oh, well. ===== NGC 2618. See IC 518. ===== NGC 2623. See IC 2386. ===== NGC 2629. See NGC 2630. ===== NGC 2630 and NGC 2631. These two objects were found by Tempel (apparently in 1883), and described in his note in AN 2660. Of the twelve novae mentioned in the note, these are the only two not listed in his table. It is remarkable, too, that he nevertheless describes them as "much brighter" than NGC 2629 and NGC 2641, both seen and measured by the Herschels and by d'Arrest. At the moment, my feeling is that Tempel confused NGC 2633 with NGC 2629, and that his pair is actually NGC 2634 and NGC 2634A. These two galaxies are the only ones in the group that are close enough to be actually called a "pair." However, while N2634 is bright enough to rival the earlier observers' discoveries in the area, N2634A is certainly not. It's just conceiveable, however, that on a night of exceptional transparency, the pair may have stood out enough to capture Tempel's attention. He was, in fact, so struck by their brightness -- compared to the nearby nebulae that the Herschel's and d'Arrest found -- that he suggested variablility for them. This is a pretty weak argument, however, so until Tempel's discovery sketch (which he mentions explicitly) can be examined, the question of the identities of these two NGC numbers has to remain open. So, I've simply entered the NGC positions in the table for the time being. ===== NGC 2631. See NGC 2630. ===== NGC 2633. See NGC 2630. ===== NGC 2634. See NGC 2630. ===== NGC 2637 is one of two galaxies found in the eastern part of the Beehive by Marth in 1864 (the other is NGC 2643, which see). Both are placed by Marth too far south by about 10 arcmin, and too far east by 6 and 18 seconds, respectively. The eight other objects that Marth found that same night show no such offsets from the true positions, but these two are reasonably consistent with each other, and are fairly close on the sky. I'll take the identifications since nothing else in the area matches. ===== NGC 2641. See NGC 2630. ===== NGC 2643 = IC 2390. This identity, first suggested by Reinmuth, was taken up by RNGC. The object was found by Marth in 1864. Correcting his position by 18 seconds of time and 11 arcmin leads to IC 2390. The IC object matches Marth's description, and there is no other object in the area (the east edge of the Beehive) that would fit better. NGC 2637 (which see), found by Marth the same night, also suffers from a declination error of 8 arcmin of the same sign, though the RA is only off by 6 seconds. ===== NGC 2652 = NGC 2974. Searching for this during ESGC, I could not find it. When I came back to the number two decades later, I tried larger errors. The galaxy finally showed up one hour later on the sky. Stone's position is otherwise about 3/4 of a minute of time further east, a common error for him and his colleagues at Leander McCormick. His description is spot-on, including the 9th magnitude star at 240 degrees position angle, 0.8 arcmin distant. ===== NGC 2653 is a double star. It was found and well-described by Tempel who placed it 12 arcmin north of NGC 2655. That is very close to the actual distance, and the identity is not in doubt. (Carlson notes that the Lick observers corrected the declination to 10 arcmin further north. There is a much fainter asterism in that position, but it does not have the eye-catching appearance of Tempel's double.) ===== NGC 2655. See NGC 2653. ===== NGC 2664, like NGC 2017 (which see), is probably not a cluster -- but it is a striking object of about a dozen stars. Villanova et al (A&A 428, 67, 2004) looked at the proper motions, radial velocities, and photometry to see if they form a cluster -- they almost certainly do not. Even so, this is an interesting object, and would probably be quite a sight at the eyepiece. ===== NGC 2666. JH's description reads only, "The chief * of a coarse cluster." There is nothing resembling this at his position (08 46 36, +47 14.8; 1950). However, a group of about a dozen stars around SAO 42564 (08 46 24, +44 53.5) does match. Could this be the "cluster" that JH found? A more thorough search of the sky at more reasonable offsets (1 hour, 10 deg, etc.) needs to be done, though. The SAO star happens to be in the same POSS1 field, but there could be other candidates in other fields. ===== NGC 2667 = IC 2410, which see. ===== NGC 2674. Though Ormond Stone had doubts about this object, his RA is just one minute of time off, and his declination is good. Aside from his note, "neb?" his estimated magnitude (16.0) and diameter (0.4 arcmin) are appropriate for the object. ===== NGC 2684. See NGC 2688. ===== NGC 2686. See NGC 2688. ===== NGC 2687. See NGC 2688. ===== NGC 2688 and NGC 2689. I've identified these using LdR's sketch. Though he saw the two objects on only one night, the sketch is a fair depiction of the sky in the area of NGC 2684. It also shows the bright galaxy, it shows NGC 2686 to be double in the correct orientation, and it shows NGC 2687 as well; all in their correct relative positions. ===== NGC 2689. See NGC 2688. ===== NGC 2696 may be MCG -01-23-004. The description and declination are close to those recorded by Stone, though the RA is about 4 minutes of time off (Stone's RA is further east -- this is in the same direction as many other of his poor positions from the first two lists of Leander McCormick discoveries). ===== NGC 2699. See NGC 2700. ===== NGC 2700, 2702, 2703, 2705, and 2707 are almost certainly all stars, with 2703 being a double. Found by Tempel (and word of them apparently sent directly to Dreyer -- I can find no mention of them in Tempel's ten papers), there are no nebulae near NGC 2699 that he might have seen. The positions given in NGC fall only near stars. The 2 deg error in the NPD of NGC 2700 is apparently a typo. The descriptions are reasonably apt for the stars, however. NGC 2700 is within an arcminute northeast of N2699, NGC 2703 is indeed "little extended" as one might expect of a double faintly seen, N2705 has three stars following it with which it forms a trapezoid, and N2702 is about 4 arcmin northeast of NGC 2699. Only NGC 2707 has no additional description (it is only "eF, S"), but its position is close to a star that might have a faint, close companion that would enhance its appearance of nebulosity. So, while the positions are not exactly on the stars, and the identities are clearly not sure, what little evidence we have suggests that they are appropriate, if not completely correct. ===== NGC 2702 is a probably star. See NGC 2700 for more. ===== NGC 2703 is a double star. See NGC 2700 for more. ===== NGC 2704 = IC 2424. This is an identity first suggested by Bigourdan who found and measured I2424 on 18 March 1892. He could not, however, find the NGC galaxy at WH's position. Since that is just a minute of time preceding I2424, the brightest galaxy in the area, the identity is almost certain. Dreyer has a note about this in his 1912 paper and in his Notes to WH's observations; he, too, accepted the identity of the two nebulae. ===== NGC 2705 is probably a star. See NGC 2700 for more. ===== NGC 2707 is perhaps a star. See NGC 2700 for more. ===== NGC 2708 is probably also NGC 2727, which see. Also see IC 2425 for a brief mention. ===== NGC 2719 may possibly be NGC 2724, which see. ===== NGC 2722 is probably also NGC 2733, which see. ===== NGC 2724 is most likely UGC 4726 with an error of almost a minute of time in RA. It's just possible, however, that the NGC number refers to NGC 2719 since JH found that during another sweep. And U4726 is as far north of JH's declination as N2719 is south (about 2 arcmin). But N2719 is another 45 seconds west of U4726, so would require a larger RA correction. Thus, my preference is to set N2724 = U4726. ===== NGC 2727 is probably NGC 2708 five minutes west at the same declination. I'm no longer convinced that this is the correct identification, but I can find nothing better in the area. The RA difference is, within JH's usual errors, exactly five minutes, and the galaxy could be called "large". However, it is not "round", but is noticeably elongated. Another curiosity concerns the next galaxy that JH found in this sweep (number 21 on 12 March 1826, an early sweep), NGC 2733. The RA for that is also uncertain, but JH marks it "+-" and has a note, "[RA] between 52m 31s and 54m 41s" for equinox 1830. This suggests that he had problems of some sort during this sweep, making it more likely that the RA for N2727 is indeed off. ===== NGC 2733 is most likely an observation of NGC 2722. JH marks his RA 08 53 00 "+-" and notes "[RA] between 52m 31s and 54m 41s" (for 1830). (His north polar distance is 93 03 54, also for 1830.) There are, however, no nebulae of any kind in this RA range that he could have seen. The declination (from his father's observations) of N2722 is the same, and the descriptions are not incompatible. Given that JH probably also had trouble with the RA for NGC 2727 (which see) in the same sweep, this is a likely identification. By the way, this is another case where the positional uncertainty that JH notes in his original list has gotten lost along the way to the NGC. In GC, the galaxy has its "Number of Observations by H and h" marked "::"; Dreyer did not carry this over into the NGC, so the position there appears as if it carries normal accuracy. Having said that, I have to also say that Dreyer has a note in his 1912 Herschel papers, and in his MN list of NGC corrections resulting from that collection, about the RA for NGC 2722. Dreyer says that the RA in the GC is too large by 44 seconds, saying that JH should probably have corrected it (as he did for other nebulae in the same sweep) to the meridian. This is indeed true, and the NGC position, corrected by the -34 seconds, lands within 9 seconds of the galaxy. ===== NGC 2736. On the SERC IIIa-J film, this appears to be the brightest patch in a supernova remnant that covers most of the 6.4 deg field with delicate whisps of nebulosity. On the ESO IIIa-F film, however, it is much brighter than the rest of the SNr, and I wonder if the relatively bright star immersed in it is exciting it as it passes by. In either case, it is certainly a diffuse gaseous nebula, not a galaxy. ===== NGC 2741. Marth's RA is 1 minute too far east. This misled Dreyer into noting the galaxy as the first of two (the second is NGC 2745, given its correct RA by Marth). Marth's declination is correct. ===== NGC 2742 is probably also NGC 2816, which see. ===== NGC 2745. Marth's position is good. Dreyer mistakenly added the note, "f of 2." See NGC 2741. ===== NGC 2753. The NGC position, from d'A, is one minute of time off. This is an improvement over N3575 and N3760, found the same night, which both have errors of 1 hour in the positions listed by d'A. See them for more. ===== NGC 2754. See NGC 2757. ===== NGC 2757 is probably a triple star. It and two other objects, NGC 2754 and NGC 2758, were found by Frank Muller at Leander McCormick in 1886 or 1887. This is one case where the Leander McCormick discovery positions are quite good, so the identities of N2754 and 2758 with two neighboring galaxies are not in doubt. However, the third position of Muller's trio falls in a region where only stars are found. Herbert Howe, working with the 16-inch at Chamberlain Observatory in Denver around the turn of the century, noticed a double star near Muller's place. This is a relatively bright (15th magnitude), wide (12 arcsec) double, and I'd be surprised if Muller mistook it for a nebula in the 26-inch, even on a night of rather poor seeing. The 26-inch is optically quite good, and will certainly show fainter objects with considerably more clarity than any 16-inch, all else being equal. About an arcminute south-south-following the double star, however, is a triple star of about the same total magnitude. The separation of the components is much less than the separation of the double's two stars. The triple was in fact picked up as a single non-stellar object by the Guide Star Catalogue software. My guess is that this is actually the object that Muller mistook as nebulous. The position, while a minute or so further from Muller's than the double star's position, is well within the usual Leander McCormick standard deviation. So, while we can't be certain about the identification (there is no surviving sketch), I'm going to take the triple as NGC 2757. ===== NGC 2758. See NGC 2757. ===== NGC 2760 might possibly be CGCG 350-021 -- there is certainly nothing near Swift's position that matches his description. In particular, he notes "nearly between *8 and *9." The stars flanking the CGCG object are at least two magnitudes fainter, so I don't want to push this identification too hard. ===== NGC 2783. See IC 2449. ===== NGC 2804 probably = IC 2455, which see. The NGC identification is not in doubt. ===== NGC 2806 is a star, and is certainly not the galaxy listed in RNGC. It is in just the place noted by Dreyer in Lord Rosse's observations. Here is Dreyer's description of the object: "A vF * or cS, eF neb p [N2809] (sky bad), forming an equilateral triangle with [2807] and [2809] (susp as neb by d'A, = [N2806])." Dreyer's descriptions and offsets for other objects in the field are exact, so there is no mistaking the true identity of N2806. ===== NGC 2807. See NGC 2806. ===== NGC 2809. See NGC 2806. ===== NGC 2816 is probably JH's second observation of NGC 2742. The first came on 8 March 1832 where the galaxy is recorded at its correct position, close to where his father placed it when he found it in 1790. JH called it "vF, pL, R, vgbM, 60 arcsec; moon very troublesome. A * 8 m np." (This compares to his father's rather more interesting note, "cB, E near par., er, bM; 4' l, 2' b. I suppose, with a higher power and longer attention, the stars would become visible." WH's "er" means "extremely mottled," which leads to his comment about the stars.) Just three weeks later, on 30 March 1832, JH swept over the area again, this time recording a "F, pmE" nebula 13m 30s to the east at the same north polar distance. There is nothing at that position, a fact first noticed by Reinmuth in his 1926 "Die Herschel Nebel." Since the declination is the same, and the description for N2816 appropriate for N2742, I'm going to suggest that the two nebulae are the same. Even though the RA difference is large, there is nothing else around that JH might have seen that makes more sense to me. Still, I'm not convinced, so I've put colons on the identification. ===== NGC 2823. See NGC 2832. ===== NGC 2825. See NGC 2832. ===== NGC 2826. See NGC 2829 and NGC 2832. ===== NGC 2827 = IC 2460, which see. Also see NGC 2832. ===== NGC 2828. See NGC 2832. ===== NGC 2829 is most likely the faint galaxy that I've included in the position table. This is tolerably close to the position shown in LdR's diagram. On the other hand, LdR's object may be a star, also close to the position in the diagram. In addition, it is sometimes identified with a faint double galaxy, but that is exactly on the line between NGC 2826 and NGC 2830 -- in the diagram, the object is off to the east of that line. ===== NGC 2830. See NGC 2829 and NGC 2832. ===== NGC 2831. See NGC 2832. ===== NGC 2832 is the brightest galaxy in Abell 779, and was seen by WH and JH. The younger Herschel also picked up another galaxy in the area, as did d'Arrest -- who also saw three others, measuring two of them -- but it remained for Lord Rosse's 72-inch Leviathan to reveal the cluster of a dozen or so galaxies around the brightest. These are NGC 2823, 2825-2834, and 2839. Note that the identification of NGC 2829 is somewhat uncertain, and that NGC 2827 = IC 2460 (which see). Lord Rosse made micrometric measurements of only six of these (with respect to the brightest), but JH received notes from the Earl that allowed him (JH) to give good positions in the GC for six others. He had to give the remaining two of the 15 claimed nebulae estimated positions. In spite of JH's care, the GC is rather confused in the area. When Dreyer came around to the group during his preparation of LdR's observations, he sorted the area out pretty well, and the NGC reflects his careful work. In the process, he dropped two of the GC numbers, and combined two others so that the total number of nebulae here seen by LdR is just 12 -- the sketch shows those twelve in their correct relative positions. Only for NGC 2829 (which see) is there any uncertainty left about the identification. Curiously, however, Dreyer put WH's observation and the brightest of JH's on NGC 2830. LdR calls the brightest "alpha", and this is clearly the third of three in short line in the center of the cluster. Yet Dreyer is apparently claiming that WH and JH saw one of the fainter galaxies here, not the brightest (Dreyer of course switches the descriptions as well). I find it odd that, given his otherwise careful treatment of the area, he should have misidentified the brightest galaxy, and not one of the fainter. However, his note in the NGC gives an alternate (and correct) numbering of the galaxies, showing that he was not convinced that he had it right in the main body of the catalogue. Finally, Dreyer has a note appended to the second of WH's catalogues of nebulae for H I 113: "A second and better obs. in Sw. 549, Mar. 28, 1876, 40 Lyncis, p. 1m 11s, s. 39'." Reducing both this and the observation in WH's main table shows that this is not a "better" observation, but is further off in both coordinates than the presumeably "worse" one (09 16 40, +33 57.9 for WH's first observation w.r.t. 66 Cancri; vs. 09 16 51, +33 57.5 for his second. The modern position is 09 16 44.0, +33 57 43). In neither case, however, is there any chance for mistaking the identification of WH's object for anything but the brightest galaxy in the cluster. ===== NGC 2833. See NGC 2832. ===== NGC 2834. See NGC 2832. ===== NGC 2837 is a double star found by JH on 16 Dec 1827. He mistook it for a nebula, perhaps on a night of poor seeing, but correctly noted that it is west of a brighter star. His estimated distance to the star was 8.5 seconds, while the actual distance is 9.2 seconds, good enough agreement that the identity can be regarded as pretty certain. ===== NGC 2839. See NGC 2832. ===== NGC 2843. In spite of the faintness of this galaxy, and its proximity to the considerably brighter star, it is almost surely the object that WH found. He is cautious in his description, noting that it took 240X to show the object and the star. His position is just an arcminute east, too, well within his usual observational error. ===== NGC 2846 is a double star. This was found by Lord Rosse (or by his observer at the time, Ralph Copeland) who thought it a star with a very small nebula nearby. Even though no accurate position is given, micrometric offsets to nearby stars positively identify the star they thought nebulous. A few years later, Lord Rosse (or Dreyer, who was then the resident observer at Parsonstown) reobserved the object, but could see no nebulosity. Instead, he suggested a very small cluster. A correction to the position, by Bigourdan, appeared in the Notes to the first IC. However, there is some error in Bigourdan's observation, since his offsets point to a blank region of sky. Just north of his position is a 15th magnitude star; another is just west. He probably saw one or the other of these. In any case, he missed Lord Rosse's double star, so we have to discount his correction. My first thought was to accept the first observation of the single star as N2846, but Glen Deen pointed out that the two star images are actually in contact on the Sky Survey. While they would not have been merged on a fairly good night at the 72-inch, they are still clearly close enough together to have misled some veteran observers into believing that one star was nebulous, or that there was a cluster present. Since the NGC itself accepts the second observation, it seems best to follow that. ===== NGC 2848. See NGC 3578. ===== NGC 2863 = NGC 2869, which see. ===== NGC 2868 is a companion to NGC 2863 = NGC 2869, which see for the story. ===== NGC 2869 is identical to NGC 2863. WH found N2863 in March of 1786, and JH observed it again forty years later. JH used his own position and most of his description in GC, but took an "average" of his and his father's brightness estimates: "vF" and "F" became "cF". All this is very close to the position and description we would make today from the Sky Survey. Dreyer copied this into the NGC. In 1885 or 1886, Frank Muller was sweeping across the field. He rediscovered N2863 and also found a fainter companion which became N2868. As usual, his positions from the circles of the Leander McCormick 26-inch refractor were so bad that he thought he had found two "novae" rather than just one. He also suggested that the RA might actually be five minutes larger than that given in the table in the AJ paper. But there is nothing in either of his positions. Herbert Howe sorted all of this out satisfactorily in a Monthly Notices note which Dreyer quoted succinctly in the Notes to the second IC. Howe also got the positions correct. ===== NGC 2871 is a star just north-preceding NGC 2872. Lord Rosse has two detailed observations of the N2872/4 group, one of which includes micrometrically measured offsets which point exactly at the star. ===== NGC 2872. See NGC 2871. ===== NGC 2874. See NGC 2875. ===== NGC 2875. This is the north-following part of NGC 2874. Lord Rosse's micrometrically measured offsets point exactly at the rather knotty spiral arm, and his description is consistent with the appearance on the Sky Survey. ===== NGC 2885 = IC 538. John Herschel saw this on only one night. The RA is marked with a plus-minus sign, and his description reads, "eF, vS, E in parallel; RA very uncertain." His description is correct, and his RA is indeed about 25 seconds too large (there is nothing in his estimated place, not even a star). The comment "... E in parallel ..." (that is, the position angle is 90 deg) fits no other galaxy in the area. This is also the brightest galaxy around, so the identification is secure. Bigourdan made four observations of the galaxy, and his position is accurate. On the other hand, he also claims to have glimpsed "NGC 2885" (on one night only; on another night, he has this as "Non vue" [not seen]) about 1.4 arcmin north of JH's place. But again, there is nothing there, not even a star. ===== NGC 2886 is probably the asterism of 4 stars about an arcminute following JH's position. There is nothing else in the area that fits his sparce description. ===== NGC 2901 may be one of the galaxies (UGC 05070, 05074, or 05087) just over a degree south of Stone's especially crude position, estimated during a search for Winnecke's comet. There is nothing closer to his position that he might have mistaken as nebulous, unless it is one of the faint double stars in the area. Wolfgang has taken one of these. ===== NGC 2902 is not IC 543 (which see for details) as suggested in MCG. ===== NGC 2903. See NGC 2905. ===== NGC 2905 is the northeast arm of NGC 2903. JH has several observations of it in that position, as well as a sketch. The only slight mystery here is why WH made it one of his first class nebulae, ranking it in brightness with the central portion of NGC 2903 itself. ===== NGC 2909 is a double star about 30 arcsec following JH's position. Several observers have suggested other identifications for it, but nothing else in the area is as convincing. See also NGC 4512 for more on the sweep in which JH found this object. ===== NGC 2911. See NGC 2912. ===== NGC 2912 is a star described only in Schultz's note for his observation of NGC 2911. The faint galaxy close following N2911 (taken as N2912 by all and sundry) is much too faint for Schultz to have picked up with his 9.6-inch refractor, especially given the considerably brighter star just a few arcsec following (the 1950 position for the star is 09 31 12.07, +10 22 57.2). Brian Skiff has suggested that N2912 is identical to N2914. But Schultz has observations of both objects on the same three nights, calling N2914 nearly as bright as N2911. Furthermore, Schultz's description of N2912 "eF, f h608 [N2911] some seconds, ab[out] 2' n, but not observable" places his "nova" northeast of N2911, not southeast. The only object in the area, bright enough that he could see, that matches his estimated offsets, is the star that I list in the table. This may not be a completely solid identification, but it is pretty close. ===== NGC 2914. See NGC 2912. ===== NGC 2932 is a patch of the Milky Way about 1 degree across, centered near JH's approximate position (he gives it only to a full minute of time and a full minute of arc). In his description, he notes that it is "... a degree or degree and half in diameter, very rich in stars of all magnitudes from 8 m downwards ..." This is just what we see on the IIIa-J plate today. ===== NGC 2938 was the first of fifteen nebulae found by WH in sweep 1096 of 2 April 1801. There was considerable confusion in the 19th century about the identities of these galaxies, confusion still not sorted out at the time the NGC and the ICs were published. It was, however, mostly laid to rest in an unsigned note in MNRAS 71, 509, 1911 "Communicated by the Astronomer Royal". This gives accurate positions for forty nebulae in the area covered by WH's sweep, and enabled Dreyer to finally publish (in the Scientific Papers) corrected NGC identifications for WH's galaxies. Dreyer, however, did not give cross-identifications to all of the NGC numbers, particularly those which came in from other observers (JH and d'A). I list those in my note to NGC 3752 (which see), where I give a fairly detailed account of the problem and its solution. ===== NGC 2944. It has seemed strange to me that just three arcmin north-following this triple galaxy is a considerably brighter pair. Did Palisa perhaps see one of the pair rather than the galaxy we now call N2944? Tracking down Palisa's original observation to AN 2782, I found that his micrometrically measured position (based on six settings) falls within three arcsec of the GSC position of brightest of the triple. The identity is thus certain -- but why did Palisa not see the brighter galaxies just to the north? ===== NGC 2947 = IC 547 = IC 2494 is the only object that I am currently (May 2003) aware of which has an entry in all three of Dreyer's catalogues. See IC 547 for details. ===== NGC 2953 is probably the star about 6 arcmin south-southeast of NGC 2954. JH found both during one of his rare excursions north of the equator during his South African sojourn on 18 March 1836. He says of this, "Suspected nebula. (N.B. These suspicions have been so constantly verified on reobservation, that I have little hesitation in registering it as an object in the catalogue.)" He adds in his description of NGC 2954, "Another suspected 6 arcmin south, nearly on the same meridian." JH gives the position only to a full minute of time and a full minute of arc; the seconds are missing in both coordinates. The star is almost strikingly isolated -- there is no brighter star within 4-5 arcminutes of it, and no galaxy or nebula aside from N2954 nearby, either. While we can't be absolutely certain about the identity -- the approximate position erodes confidence -- the lack of any other candidate matching JH's description lends considerable credibility to the star. ===== NGC 2954. See NGC 2953. ===== NGC 2972 = NGC 2999, which see. ===== NGC 2973 is perhaps the triple star just following JH's position. If it is indeed the correct object, JH's note "a B * 8 m follows" is somewhat misleading since the star is clearly south-following. That raises the possibility that the double star also listed in the table is JH's object. However, JH describes his object as "eF, 40 arcsec." The triple is closer to that size than the double. So, both asterisms are candidates. For the present, I favor the triple -- but not by much. ===== NGC 2974 is also NGC 2652, which see. ===== NGC 2977 was one of the galaxies found by WH on the night of 2 April 1801 for which large, systematic errors exist in the position. See NGC 3752 for more information. ===== NGC 2979 = NGC 3050, which see. ===== NGC 2984 = IC 556, which see. ===== NGC 2995 appears to be a clump of stars roughly 20-25 arcmin across centered about 10 arcmin north of JH's position. His description reads "Cluster VIII class, at least 20 sts 11 m and upwards, and many smaller." This is what we see on the IIIa-J plate, though I doubt that it is a real cluster. ===== NGC 2998. See NGC 3000, 3002, 3004, and 3008. ===== NGC 2999 = NGC 2972. JH's place for N2999 is only approximate. He says, "Observed for Dunlop 397, and place only rough. Possibly the same object with Sw 680, No. 27, which see above (No. 3183 [= N2972])." This is an entirely reasonable hypothesis, and JH's descriptions are the same, so I've adopted the identity. =====