NGC 2854 in Ursa Major
February 2026 - Galaxy of the Month
For my choice of galaxies for the February GOM I have chosen the galaxy triplet NGC 2854, NGC 2856 and NGC 2857 in Ursa Major. The first two were discovered by William Herschel in 1788 but it took until 1856 that Mitchell using Lord Rosse’s 72” telescope at Birr found NGC 2857. He also noted the galaxy CGCG 238-051 (PGC 26694) next to it although Dreyer did not include that galaxy in the NGC.
All the galaxies are of spiral form with NGC 2857 being a face on spiral with a small well-defined core which explains its faintness. Herschel thought NGC 2854 and NGC 2856 were very faint as well.
The group were also catalogued by Arp with NGC 2854 and NGC 2856 coming under Arp 285 designation and NGC 2857 as Arp 1. With NGC 2857 Arp thought of it as part of his group of low surface brightness spirals and NGC 2854 and NGC 2856 were catalogued as a double galaxy with infall and attraction features.
The group are not physically associated, with NGC 2854/56 thought to lie at a distance of perhaps 40 Mpc and NGC 2857 almost twice as far away at 73 Mpc. The galaxies are also included in the galaxy group WBL 221, which contains 7 galaxies including NGC 2857, although as noted this galaxy is twice as far away as the others. NGC 2857 is also included in the 11 galaxy group LGG 168 (which does not include NGC 2854 or NGC 2856).
The strong UV signals shown in the GALEX observations from all three galaxies suggest that there is a lot of star formation going on in them. The UV observations also suggest tidal tails being drawn out from NGC 2854, probably from its interaction with NGC 2856. There is also possibly a string of material, originally thought to be a jet, being drawn out from NGC 2856 that is best seen in the UV as well, although there are signs of it on both the SDSS and PanSTARRS images as well. It is not however a jet but a series of star forming complexes. The material to form these would have been accreted from NGC 2854.
There are suggestions that on the larger cosmological scale these galaxies may be part of the galaxy filaments associated with the Virgo galaxy cluster.
The whole group is quite tight and will fit in the field of view of a modern hyperwide eyepiece at 265x. Perhaps as expected the group does not appear in any of the common lists although it is included in Alvin Hueys guide to Galaxy Trios available from his website. NGC 2857 has a small bright core and this is probably all that most people will see. Perhaps surprisingly as they are Arp objects they are not included in the The Night Sky Observer's Guide Vol. 2. Alvin Huey in his guide to the Arp objects suggests that in 22” Arp 1 is very faint with only a core seen. Arp 285 is much easier to see but no structure is visible. Those with larger telescopes or EAA systems might like to see if they can find PGC 26694.
Owen Brazell - Galaxy Section Director
If you'd like to try out the Clear Skies Observing Guides (CSOG), you can download observing guide for the current Galaxy of the Month without the need to register. CSOG are not associated with the Webb Deep-Sky Society but the work of Victor van Wulfen.
