The past year I have been involved with updating the databases used in several computerized setting circles marketed by Celestron, Lumicon and JMI. While working on these projects, I found many new identification inaccuracies, particularly with regard to southern deep sky objects that I had not yet visually observed. Two sources which proved very helpful in this regard were the ESO-Uppsala Catalogue and the expanded Surface Photometry Catalogue of the ESO-Uppsala Galaxies as they provided, for the first time, precise positions and magnitudes for many faint southern galaxies and in some cases gave alternate NGC identifications.

In this paper, 26 cases are reviewed involving errors involving 31 RNGC listings. This yields a total of 113 cases encompassing 148 errors in this series of articles. I’d like to thank identification experts Malcolm Thomson and Dr. Corwin from the California Institute of Technology for double checking many of these listings and adding their own insights.

NGC 207: The RNGC classifies this entry as type 7 or nonexistent. Lord Rosse discovered this object near N210 and described it in two observations made on 7 December 1857, and 29 October 1877. With respect to N210, he placed his "Nova" 25'± south and about 35s of RA west. The description from 1877 reads "vF, S, lE pf, mbMN, stellar 5' nnf a coarse double star 10-11 and 12m."

The precise 1950 coordinates for N210 are 00 38 04.0 -14 08 54. Using Rosse's offset from N210 places N207 at approximately 00 37.5 -14 34 (1950). The galaxy M-03-02-035 is located at 00 37 09.8 -14 30 44 (1950) which is a close enough match given Rosse's rough offset. Furthermore, this galaxy is also elongated E-W and is located 5' NNW (incorrectly given as NNE) a wide double star at 40" separation matching the visual description from 1877. So, the identification N207 = M-03-02-035 is certain.

N207 is incorrectly listed as nonexistent in RNGC and the type of N207 should be changed to "5" (galaxy) in the RNGC, the position to 00h 38.4m -14 23' (1975) and the new description updated to describe M-03-02-035 .

NGC 336: Leavenworth discovered this galaxy at the Leander-McCormick observatory with a 26" refractor. Although the RA from the first discovery paper in AJ, 7, 146 are generally very poor (given to the nearest minute and often incorrect by a few minutes of RA), Leavenworth also discovered N335 whose position is fairly accurate so we can use it as a fixed reference. Leavenworth placed N336 just 9' south of N335 although the galaxy chosen by the RNGC is located 30' south of N335.

According to Dr. Harold Corwin who examined the original discovery sketch, N336 is a very faint peculiar galaxy or a colliding pair with three nearby stars whose relative position accurately matches the discovery sketch. The ESO-Uppsala catalogue lists this galaxy as E541-IG2 at 00h 55m 35s -18 39.4' (1950). This places N336 exactly 9' south of N335 and perfectly matches Leavenworth's offset.

The RNGC incorrectly identifies N336 with an anonymous galaxy M-03-03-011 located 30' south of N335. The RNGC coordinates should be changed to 00h56.8m -18 31' (1975) and the data changed to describe E541-IG2.

NGC 408: Herman Schultz placed this object 8s of RA preceding N410. In this position on the POSS is a mag 14.5 star with GSC position 01 10 51.1 +33 09 05 (2000) that almost certainly is Schultz's object. The RNGC has instead misidentified N408 as an anonymous galaxy having the same RA but also 3' south of N410. Since Schultz micrometric measurement placed his “nova” due west of N410 the RNGC identification is very questionable and more likely N408 is a star. Dorothy Carlson, in her 1939 article on NGC errata, also came to this conclusion based on Mt Wilson photographs although Reinmuth describes this object as a “nebulous *14.”. Finally, the RNGC has misinterpreted the NGC description to read “406 F 8S” instead of “410 F 8S”.

NGC 464: Discovered by Wilhelm Tempel with an 11" refractor and placed at 01 19 33 +34 57.7 (2000). The RNGC identifies N464 with an extremely faint galaxy located 6' west of Tempel's position. According to Bigourdan who searched for N464, Tempel's entry may refer to a small asterism of four stars close northeast. But just 1' W of the NGC position for N464 is a 9" double of 14th magnitude stars with a mean GSC position of 00 19 26.7 +34 57 20 (2000). Interestingly, my visual observing notes indicate that I thought the close faint double could possibly be a non-stellar object with my 17.5". Due to the faintness of the RNGC candidate and the nearby imposters it is likely that Tempel's N464 is nonexistent (either a close double star or a Bigourdan's group of 4 stars).

NGC 1188: This is the one of a group of five galaxies recorded by Leavenworth including N1189, N1190, N1191 and N1192. Although Leavenworth gave only a single rough RA for these objects (corrected by 3 min of RA in a note in the second discovery list), Howe provided precise individual RA's which were listed in the notes and corrections section of the IC2. Howe's position for N1188 is 03 01 23 -15 41 46 (1950) and very close to these coordinates is M-03-08-068 with a GSC position of 03 01 23.0 -15 40 46 (1950). It is interesting to note that this places N1188 just 8' N of N1199 which is the brightest member of the compact group Hickson 22 including Leavenworth's N1189-92.

The RNGC incorrectly lists N1188 as nonexistent and Sulentic identifies it as equivalent to N1199. Conclusion: Change the type of N1188 to 5 (galaxy) and the 1975 coordinates to 03h 02.6m -15 35' (1975). All data needs to be updated to reflect the position, magnitude and photographic appearance of M-03-08-068.

NGC 1692: This is another Leander-McCormick observatory discovery found by Ormond Stone. His very rough discovery position to the nearest minute of RA is 04 51.5 -20 38 (1950). The RNGC identifies N1692 as a faint galaxy at GSC position 04 52 22.5 -20 37 58 (1950), with a trio of faint stars close south. The Southern Galaxy Catalogue and ESO catalogues identify N1692 with the larger and brighter galaxy E552-G21 = M-03-13-029 at 04 53 14.1 -20 38 59 (1950). Although Ormond Stone's position is closer to the galaxy identified as N1692 in the RNGC, Harold Corwin has examined Stone's discovery sketch and confirms that N1692 = E552-G21 = M-03-13-029. This places N1692 roughly 2 min of RA following Stone's position, a typical error found in his list. Conclusion: Change the position of N1692 in the RNGC to 04h 54.3m -20 37' (1975) and update the data to describe E552-G21.

NGC 2326: This galaxy is located at 07 04 18.9 +50 45 40 (1950). The RNGC has a poor position and places it 0.3 minutes of RA further east and 3' north. So, the RNGC position should be changed to 07 06 15 +50 43.3 (1975). N2326A, located just 4.8' southeast, is correctly placed in RNGC.

NGC 2330, 2332: N2332 is one of the brighter members of a group of galaxies stretching some 15' east including N2340 and a number of IC entries micrometrically measured by Kobold. William Herschel observed two galaxies in the group (II 862 and II 736) which Dreyer listed as N2332 and N2340 in the NGC. In Scientific Papers of William Herschel, Dreyer notes regarding II 862, "identification difficult, as it is one in a group. It is probably one of Kobold's nebulae in the IC." In any case, John Herschel definitely observed N2332 = h430 and Dreyer used his correct position in the NGC, so the identification is certain.

In the three Lord Rosse observations of the field a total of 9 objects were found and sketched. For some reason the only additional object that Dreyer decided to include in the NGC was N2330. Swift and Kobold later surveyed the field, and Dreyer included accurate positions for all of Rosse's objects shown on the sketches in the IC.

Since Rosse did not provide positions, Dreyer probably had to rely on the sketch The NGC position for N2330 is incorrectly given as 2.4' north of the larger and brighter N2332. It appears that this error originated from one of the Rosse sketches which incorrectly placed N2330 north of N2332 instead of southwest. N2330 was then properly sketched at a later observation and recatalogued by Dreyer as IC 457. Therefore, it is fairly certain that N2330 is identical to IC457. The 1950 positions for these galaxies are

N2330  07 05 37.9 +50 13 59  =IC 457 = M+08-13-078 = Z234-074
N2332  07 05 43.7 +50 15 46  =U03699 = M+08-13-079 = Z234-075

The identifications and positions given in the RNGC are

(R)N2330  07 05.7 +50 16  E, R, BM, DKLNSUSP
(R)N2332  07 05.7 +50 15  E, R, BM, ALMSTEL

Based on the RNGC declinations it is clear the RNGC has reversed the identifications of N2330 and N2332 making N2330 the brighter northern member of the pair and incorrectly describing N2332 as "almstel" (same error in MCG). So, the data for N2330 and N2332 should be reversed in the RNGC and the comment "=IC 456" added to the N2330 notes column.

NGC 2426: John Herschel placed this galaxy (discovered by his father, William) at 07 39 27.3 +52 27 03 (1950). UGC, MCG and CGCG identify N2426 = U03977 = M+09-13-038 = Z262-022 at 07 39 26.4 +52 26 16 (1950) which is a perfect match with Herschel's position.

The RNGC declination is offset exactly 30' too far north and should be changed to +52 23' (1975). Because of the RNGC error, this galaxy is also misplotted on the U2000.0 star atlas. Ralph Copeland, using Lord Rosse's telescope, discovered N2429 5' northeast.

NGC 2529, 2530, 2531: The first of this trio to be discovered was N2530 by William Herschel (III 752). His son, John, accurately placed it at 08 05 04.8 +17 58 16 (1950) which is an exact match with U04237 = M+03-21-020

The RNGC incorrectly lists N2530 as nonexistent although the data for the galaxy is found under the entry for N2529. Also, the RNGC coordinates for N2530 and N2531 are grossly in error by over 1 hour and 40 minutes in RA and 7 in declination.

The NGC entries for N2529 and N2531 derive from observations by Bigourdan who examined the field of N2530 on four occasions and on one night logged two very faint companions that he placed 1' southwest and 1' southeast of N2530. Reference to the POSS reveals there are no objects at either position, so these numbers should be listed as nonexistent.

Other catalogues are also in error. The CGCG equates Herschel's III 752 = N2530 with both h N2529 and N2531 although Bigourdan was not confused on the identity of N2530. Also, the UGC states N2529 = N2531.

So, N2529 should be reclassified as nonexistent in the RNGC. The position of N2531 should be changed to 08h 06.4m +17 54 (1975), although the type 7 designation (nonexistent) is accurate. Finally, the information given in the RNGC under N2529 should be transferred to describe N2530, so that N2530 is catalogued as the one galaxy at this position.

NGC 2736: On 1 March 1 1835, John Herschel discovered this object at the Cape of Good Hope and described it as "eeF, L, vvmE; an extraordinary long narrow ray of excessively feeble light; position 19 ±. At least 20' long, extending much beyond the limits of the field...". This agrees perfectly with the ESO- Uppsala listing N2736 = E260-N14, a nebula with dimensions 30'x7', position angle of 20 and notes "Luminous filament". Harold Corwin adds that on the ESO IIIa-F film this nebula is the brightest patch of a huge supernova remnant (Gum Nebula) whose delicate whips cover the field. A relatively bright star is immersed in N2736 (mentioned by Herschel).

The RNGC lists this object as a galaxy although there is no photographic description. The type of N2736 should be changed from 5 (galaxy) to 3 (diffuse nebula).

NGC 2973: John Herschel recorded this object on 5 Feb 1837 from the Cape as "eF, pS, *8 f" and placed it at 09 41 31.4 -30 02 50 (2000). Reference to the POSS reveals a close triple star with GSC position 09 41 32.4 -30 5 22 (1950). In addition, there is a mag 8 star 4' due east matching Herschel's description.

The RNGC and ESO identify N2973 = E434-G16 at 09 37 59 -30 08.9 (2000) although this galaxy is 3.5 minutes of RA preceding Herschel's position and 6' south. Furthermore there is no corresponding bright star to the east. The U2000.0 atlas follows suit and incorrectly plots N2973 at the position of E434-G16.

Since this object is nonexistent the RNGC type should be changed to 7 and the new description should read "=***".

NGC 3855, 3856: This close pair was discovered by d'Arrest. The declination is listed as uncertain in the NGC although Dreyer gave a more accurate position (from Spitaler) for N3855 at 11h 41.6m +33 37' (1950) and N3856 at 11h 41.8 +33 37' in the Notes and Corrections section of the IC 1. At this exact position on the POSS is a pair of galaxies that were later reentered into the IC 2 as IC 2952 and IC 2953 (accurately placed by Javelle) with the following object (IC 2953) both larger and brighter.

UGC, MCG and CGCG identify these two galaxies with the IC designations since the IC identifications are certain and the RNGC, MCG and CGCG identify N3855 = M+06-26-028 = Z186-036, a very small galaxy located 5' SE of the close pair, while N3856 is listed as nonexistent in the RNGC. It seems very unlikely that this was the single galaxy seen by d'Arrest as IC 2953 (15.1z) in the same field is both larger and more prominent visually than M+06-26-028 (15.6z), based on my 17.5" observation.

If we accept Spitaler's corrected positions in the IC 2 notes, then N3855 = IC 2952 and N3856 = N2953 and the RNGC, MCG and CGCG have misidentified both numbers with M+06-26-028 = Z186-036. It is also possible that N3855 = IC 2953 and N3866 = M+06-26-028 and this was apparently the interpretation given by Bigourdan in his observation of the field. In the first case, the position of N3855 should read 11h 42.9m +33 29 (1975) and N3856 as 11h 43.0m +33 29' (1975) and noted as identical to IC 2952 and IC 2952, respectively.

NGC 4202: Discovered by David Todd during his search for a trans-Neptunian planet (AN 2698). Dreyer only included eight of the 30 objects which Todd sketched as many were considered doubtful or near nebulae already catalogued. Todd's sketch of object 18, which includes several nearby field stars, clearly identifies N4202 = U07337 = M+00-31-046 at GSC position 12 18 08.6 -01 03 52 (2000). This means that Todd's rough position used in the NGC was 3 minutes of RA too far west although a number of his entries have large errors in RA.

The RNGC misidentifies N4202 = Z013-109 at 12 14.9 -02 27 (2000) and early versions of U2000.0 atlas have it misplotted at this position. The 1975 coordinates for N4202 should be changed to 12 16 52 -00 55.5 and data changed to describe U07337 (dimensions 1.2'x0.7' in position angle 127 , mag 14.4B).

NGC 4823, 4829: Tempel discovered the trio of N4820, N4823, N4829 just south of N4825. N4820 was placed in the NGC at 10s west and 3.4' south of N4825, N4823 was placed 4s west and 0.4' south and N4829 at 12s east and 4.4' south. These positions may have been communicated directly to Dreyer and appear to be approximate as Tempel's AN No. 2439 paper only mention "three more faint nebulae south of N4825."

The RNGC lists NGC 4823 as nonexistent but the POSS shows that N4825 does have three companions and an a logical assignments of identifications is:

N4820 12 57 00.5 -13 43 10  =M-02-33-067
N4823 12 57 25.6 -13 41 56
N4829 12 57 24.4 -13 44 15

This places N4823 20s following the (approximate) NGC position and 2.3' north of N4829. Additionally, the RNGC description for N4829 ("spindle, stellar nucleus") appears to describe N4823 instead of N4829 2' to the south. So, the type of N4823 should be changed to 5 in the RNGC and the position to 12h 56.1m -13 34' (1975). The new description and other data need to be updated to refer to this galaxy. The new description of N4829 should be changed to describe the correct galaxy.

NGC 5086: In April of 1837, John Herschel discovered this galaxy at the Cape within a group including N5082, N5090 and N5091. He described N5086 as "eF, R, 15", the 2nd of a group of 4" and placed it 9s of RA west and 0.7' south of N5090, the brightest in the group. Herschel recorded N5086 on only one occasion while the other three members were viewed twice. Located 9s preceding N5090 is a pair of mag 14-15 stars at 17" separation which Herschel probably mistook as nebulous. Alternatively, ESO identifies N5086 = E270-G1, which is an extremely faint galaxy located at 13 20 55.5 -43 44 21 (2000). This galaxy is 12s west of N5090 but 2' south. It is also 1.5' south of N5091 although Herschel's declination indicates N5086 is north of N5091. So, this interpretation is less likely.

The RNGC identifies N5086 = E270-G3, which is located 3.4' due south of N5090 and this identification is clearly in error. Change the type to 7 in the RNGC and the new description to "=**", although it is possible that N5086 = E270-G1.

NGC 6111: The NGC coordinates (obtained by Dreyer from Lewis Swift in private correspondence) are 16 14 25 +62 21 20 (2000). This object was never formally entered in any of Swift's discovery lists prior to the NGC. However, in Swift's list IX in Astronomische Nachrichten 3004, he published a corrected position for N6111 (object #57) at 16 14 16 +63 16.2 (2000). This position corresponds with Z320-014 = M+11-20-007 at 16 14 22.5 +63 15 40 (2000). His description "D* nr s points to it" clinches the identification as this galaxy is collinear with a faint double star 3' south (mag 13/14.5 at 18").

Bigourdan measured what he thought might be N6111 at 16 15 29 +62 44 (2000), which is given in the IC 2 notes section but Malcolm Thomson measured Bigourdan's offsets carefully and arrived at a close double star.

The RNGC misidentifies N6111 = IC 1210 at 16 14 30.8 +62 32 15 (2000). Coincidentally, Swift also discovered IC1210 and it is placed correctly in List IX. So the position of N6111 should be changed to 16h 14.1m +63 19' (1975) and the data changed to describe Z320-014 = M+11-20-007.

NGC 6816: On July 30, 1834, John Herschel reported the discovery of a galaxy at 19 43 59.5 -28 33 04 (2000) Near this position are two galaxies with a 5' separation; E460-G29 at 19 43 59 -28 29.2 (2000) and E460-G30 at 19 44 02 -28 24.1 (2000). RNGC and ESO identify N6816 = E460-G30, although if you compare Herschel's coordinates the southern galaxy E460-G29 is a closer match.

RNGC and ESO was probably influenced by the NGC description of N6816 that mentions a "* north preceding." There is a 9th magnitude star just west of E460-G30 and a close pair of faint stars on the west and northwest edge of the galaxy. E460-G29 is located 5' south of this 9th magnitude star.

John Herschel's original Cape observation reads "eF, R, vlbM, 40", a *9 magnitude north of it, at 6' distance has what may be easily taken for a nebula attached to it, but it is only a little group of vS stars." Based on this description, there can be no doubt that the southern galaxy E460-G29 = N6816. Herschel probably observed E460-G30 near the mag 9 star but felt it was only a group of faint stars.

In my 17.5", I found E460-G29 to be visually more prominent as the close stars involved with E460-G30 confuse the observation. So, the RNGC position should be changed to 19h 42.4m -28 33' (1975) and data updated to describe E460-G29 (dimensions 2.2' x 1.0' in position angle 107 , mag 14.2B).

NGC 6901: Discovered by Marth in July of 1862 but given a poor position of 20 21 15 +06 27.5 (2000). No object exists at his position but 1 minute of RA following is U11542 = M+01-52-002 at 20 22 21.5 +06 25 48 (2000) which is identified as N6901 in RNGC. For some reason, the New Description reads "not found", although the photographic magnitude is 14.9, well within Marth's range, and I observed this galaxy in my 17.5". Assuming Marth made a 1.0m error in RA, then N6901 = U11542 = M+01-52-002.

To complicate matters, Bigourdan was misled by Marth's poor position and reobserved this galaxy as IC 5000 on 29 September, 1891. Nearby IC 1316, also logged by Bigourdan on the same evening is nonexistent. The CGCG identifies U11542 as IC 1316 while the UGC states IC 1316 = IC 5000 but both catalogues ignore the NGC designation! RC2 and RNGC equate all three numbers, N6901 = IC 1316 = IC 5000.

Although the RNGC probably has the correct identification for N6901, the equivalence with IC 1316 should be removed and a photographic description added.

NGC 6999: Marth discovered a pair of galaxies, N6998 and N6999 in April 1864 which he oriented NW- SE. N6999 was placed 22s of RA east and 2' south of N6998 which has coordinates of 21 01 37.7 -28 01 55 (2000). Applying Marth's offset points exactly at E464-G15, located at 21 01 59.6 -28 03 32 (2000). This difficult galaxy was just visible in my 17.5" due to its low surface brightness. For some reason RNGC has identified N6999 with an anonymous galaxy located 10' north of N6998 which is an obvious error.

The coordinates for N6999 should be changed to 21h 00.5m -28 09' (1975) and the data to E464-G15.

NGC 7108: This Marth entry was placed at 21 40 55 -06 46 (2000). There is no object at this position but exactly 1.0 min of RA following is N7111, correctly placed by Stephan at 21 41 53.8 -06 42 32 (2000). The galaxy identified as N7108 in the RNGC is a virtually stellar galaxy surrounded by several faint stars and located over 20 arcmin following Marth's position and 12' ESE of N7111.

The simplest solution here is to assume a 1.0 min error in RA by Marth, and equate N7108 = N7111. Although faint, this galaxy was easily visible in my 17.5". In this case, the type should be changed to 7 and the new description "=N7111".

NGC 7268: On 27 September 1834, John Herschel described this galaxy as "vF, S, R, the preceding of 2" with N7277 and he placed it 30s of RA preceding N7277 and 3' south. A later observation on 18 August 1835 confirmed this separation. In compiling the NGC, Dreyer accidentally placed N7268 1.5 minutes of RA west of N7277 and no galaxy exists at this position. But exactly at Herschel's original offset from N7268 is the double galaxy E467-IG57 = M-05-53-001/002 at 22 25 41.0 -31 12 02 (2000). This galaxy is identified as N7268 in ESO, SGC and NGC 2000.0.

The RNGC clearly misidentifies N7268 (possibly as E 467-IG55) as the stated position is 14' south and 1.0 minute of RA preceding N7277. The coordinates of N7268 should be changed to 22h 24.3 -31 20' (1975) and data to E467-IG57 (dimensions 1.5' x 0.6 in position angle 125 , mag 14.1B).

NGC 7349: This is another discovery at the Leander-McCormick observatory from Frank Muller. His rough position is 22h 41.5m -22 54' (2000) and description; mag 15.0 (nucleus), 0.3' x 0.1', position angle 175 , binuclear or double. There is no object at this position but 1 north is E603-G4 = M-04-53- 029 located at 22 41 15 -21 47.7 (2000) which is identified as N7349 in ESO and SGC but not MCG. Although Muller's declination is considerably off, his position angle is very close to the ESO position angle of 166 and provides a reliable check.

The RNGC identifies N7349 = M-04-53-036 located 3.3 minutes of RA east and 8' south of Muller's place. Neither galaxy is close to the original position, but the ESO galaxy fits the visual description. The RNGC coordinates should be changed to 22h 39.9m -21 56' (1975) and the data for E603-G4.

NGC 7521, 7524: This pair of galaxies was discovered by Marth, who placed N7521 (m535) at 23 13 35 -01 44 (2000) and N7524 (m537) at 23 13 47 -01 44. This puts N7521 due west of N7524 by 12s of RA. His positions and relative separation very accurately match N7521 = M+00-59-009 at 23 13 35.3 - 01 43 53 (2000) and N7524 = M+00-59-010 at 23 13 46.6 -01 43 49.

The RNGC positions need to be slightly modified to N7521 at 23 12.3 -01 52 (1975) and N7524 at 23 12.5 -01 52. The CGCG completely misplaces the position of N7524 by over 5 and apparently this large error was repeated in the RNGC rectangular coordinates for N7524.

NGC 7554, 7556: This faint galaxy is one of the close companions of N7556 (discovered by William Herschel) in a large group near the Pisces-Aquarius border. Marth's description reads "eF, eS, alm stell, near h2220 [N7556]" and his position for N7554 is just 3s of RA preceding N7556. At this exact separation from N7556 is a compact companion. The GSC 2000 positions for these galaxies are N7554 at 23 15 41.4 -02 22 43 and N7556 at 23 15 44.4 -02 22 54.

Based on the listed RA and Dec, the RNGC appears to misidentify N7554 with a faint galaxy 5' southwest of N7556 although there may simply be an error in position for N7556 as the rectangular coordinates do not match. In an observation with my 17.5", the only companion to N7556 I could detect was the galaxy 45" WNW which was listed by Marth as N7554.

The position for N7556 should be changed in the RNGC to 23 14.5 -02 31 (1975)

Bibliography

1.	Gottlieb, S.; W.S.Q.J. No. 80, April 1990.
2.	Gottlieb, S.; W.S.Q.J. No. 76, April 1989.
3.	Gottlieb, S.; W.S.Q.J. No. 72, April 1988.
4.	Gottlieb, S.; W.S.Q.J. No. 64, April 1986.
5.	Sulentic, J. & Tifft, W.; ‘A Revised New General Catalogue’, 
        University of Arizona Press, 1973.
6.	Dreyer, J.L.E.; ‘New General Catalogue...’, R.A.S., London, 1888.
7.	Herschel, J.F.W.; ‘Results of Astronomical Observations made during 
        the years 1834, 5, 6, 7, 8, at the Cape of Good Hope...’, 
        Smith, Elder and Co., London, 1847.
8.	Rosse; ‘Observations of Nebulae & Clusters of Stars...’, Royal 
        Dublin Society, Dublin, 1880.
9.	Lassell, W. (Marth); ‘A Catalogue of new Nebulae discovered at 
        Malta with the Four-foot Equatorial in 1863 to 1865’, 
        Memoirs of the R.A.S., Volume 36, 1866-67.
10.	Nilson, P.; ‘Uppsala General Catalogue of Galaxies’, Uppsala, 1973.
11.	Zwicky, F.; ‘Catalogue of Galaxies & Clusters of Galaxies’, 
        Calif Institute of Technology, 1961-68.
12.	‘Palomar Observatory Sky Survey’, National Geographic Society, 
        Calif Institute of Technology, 1954.
13.	Sinnott, R.; ‘NGC 2000.0’, Sky Publishing Corporation, 1988.
14.	Lauberts, A. and Valentijn, E.; ‘The Surface Photometry Catalogue 
        of the ESO-Uppsala Galaxies’, European Southern Observatory, 1989.