Galaxies NGC 2857 (Arp 1) & NGC 2854/6 (Arp 285)
History
On 9 March 1788 William Herschel found two nebulae with his 18.7 inch reflecting telescope. He cataloged them as III 713 and III 714 (class III = very faint nebulae). He noted both as «considerably faint, considerably small, little extended». [464] Later in 1888 Dreyer cataloged nebula III 713 as NGC 2856 and nebula III 714 as NGC 2854. [313]
The pretty face-on spiral nebula nearby was obviously overseen by Herschel. It remained unnoticed until 9 January 1856 when the Irish astronomer R. J. Mitchell, an assistant to William Parsons, 3rd Earl of Rosse, discovered it with the giant 72 inch «Leviathan of Birr Castle». [277] Dreyer cataloged it in 1888 as NGC 2857 and added the description: «very faint, pretty large, 4 stars preceding.» [313]
In 1966 Halton Arp published his «Atlas of Peculiar Galaxies», where he ordered galaxies into groups based on purely morphological criteria. The galaxy NGC 2857 was the first entry in his catalog in the first group «spiral galaxies, low surface brightness» (group #1-6). He just remarked: «High contrast print of low surface brightness spiral.» The pair of galaxies NGC 2854 and NGC 2856 received the designation Arp 285, classified as «double galaxies, infall and attraction» (group #281-286). He remarked: «Narrow tail leads away from northern nucleus.» [199]
Physical Properties
Simbad lists a distance of 73 Mpc for NGC 2857, 40 Mpc for NGC 2856 and 25-42 Mpc for NGC 2854. [145]
| Name | RA | Dec | Type | bMag | vMag | B-V | SB | Dim | PA | z | D(z) | Dreyer Description | Identification, Remarks |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NGC 2854 | 09 24 02.9 | +49 12 14 | Gx (SBb) | 13.8 | 13.0 | 0.8 | 12.8 | 1.6 × 0.6 | 50 | 0.009243 | 39.04 | cF, cS, vlE, pglbM | WH III 714; h 589; GC 1833; UGC 4995; MCG 8-17-92; CGCG 238-46; IRAS 09206+4925; Arp 285; KUG 0920+494A |
| NGC 2856 | 09 24 16.2 | +49 14 57 | Gx (Sbc) | 14.0 | 13.2 | 0.8 | 12.4 | 1.1 × 0.5 | 134 | 0.008799 | 37.17 | cF, cS, lE, bM | WH III 713; h 591; GC 1836; UGC 4997; MCG 8-17-93; CGCG 238-47; IRAS 09208+4927; Arp 285; KUG 0920+494B |
| NGC 2857 | 09 24 37.7 | +49 21 26 | Gx (Sc) | 12.9 | 12.3 | 0.6 | 13.7 | 2.2 × 2 | 138 | 0.016301 | 68.85 | vF, pL, 4 st p | GC 1834; UGC 5000; MCG 8-17-95; CGCG 238-49; Arp 1 |
Finder Chart
The galaxy NGC 2857 is located in the constellation Ursa Maior. The best viewing time is November to July when this circumpolar constellation is highest at night.
