Type | Galaxy |
---|---|
Magnitude | 13.08 |
Size | 0.75' x 0.54' @ 90° |
Right Ascension | 0h 36' 28.9" (2000) |
Declination | 10° 6' 22" S |
Constellation | Cetus |
Description | F, L, st in centre, f of 2 |
Classification | SA_B |
Harold Corwin
Steve Gottlieb, re-reducing William Herschel's observation, has found that H III 954 is probably not NGC 163 as Dreyer supposed, but could well be this galaxy, the following of a pair. William Herschel's reduced position falls much closer to this than to NGC 163, though a little doubt remains as William Herschel's description is sparse: "eF, S, excessively F". William Herschel has another galaxy (NGC 153) in the same sweep, with offsets from the same star (8 Ceti). William Herschel's position for that galaxy is good, so we can presume that -- barring a blunder -- his position for III 954 is also good.
NGC 163 was found by d'A and measured by him on two nights in Sept 1865; his position is accurate. He assumed that he saw the same galaxy as William Herschel, and notes the 32 second difference in the RAs.
Both galaxies were seen by Tempel. In his paper (in AN 102, 225, 1882 = AN 2439) he says, "Following III 954 -- observed by [William Herschel] and d'A -- by 30 [seconds of time] is a larger though fainter nebula with a star in the middle; a small star follows the nebula close to the north." Tempel clearly thought that William Herschel and d'A had seen the same galaxy, and that his second object was a "nova". Dreyer adopted this interpretation for the NGC.
Finally, Swift has an observation of one nebula here on 9 August 1886. His position, 00 36 14, -10 07.3 (precessed to J2000), is a almost exactly midway between the two galaxies. Note, however, that the RA's of the galaxies found on this night are 10-15 seconds of time too large, so this is almost certainly an observation of NGC 163, as assumed by Dreyer. Swift's description "eF, vS, R; v diff; only 1 * v near" could apply to either object, but fits NGC 163 well enough.
So, to summarize, William Herschel and Tempel saw NGC 165; while d'A, Tempel, and Swift saw NGC 163.― NGC Notes by Harold Corwin
Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.
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