Object name: ARP310
Designation(s): ARP310, ARP311, IC1258, IC1259, IC1260,
ARP 310 and 311 is an odd combination in Arp's catalog. Arp 310 consists of IC 1259, a close pair of galaxies. Arp 311 consists of Arp 310 and adds IC 1258 to its southwest and IC 1260 to its southeast. Arp 310 is classed under Group Character: Galaxy pairs while 311 is under Group Character: Galaxy Groups. There are other galaxies in the area but as far as I can determine they aren't included in 311 by Arp. Arp 311 is also known as WBL 640 and is listed by NED as consisting of only 4 galaxies. But the SDSS lists a cluster centered on Arp 310 called SDSS-C4-DR3 3143 consisting of 47 members. It puts the average redshift for the group at 8394 km/s while that of Arp 310 is a bit less at 8100 km/s. The difference is insignificant as relative motion within a cluster can easily exceed this difference. So apparently the group is much larger than Arp realized. Using this latter redshift the distance to Arp 310-311 would be about 375 million light-years. Arp's comment on Arp 310 was simple that it consisted of two close elliptical galaxies. He had nothing to say about Arp 311. These galaxies are located near the head of Draco, just east of the Draco Dwarf Galaxy, a satellite galaxy of our Milky Way Galaxy that is one of the dimmest galaxies known consisting mostly of "dark matter" and a handful of stars.
Related Designation(s):1RXS J172716.9+582908, 2MASS J17271737+5829079, 2MASS J17273171+5828330, 2MASX J17271733+5829078, 2MASX J17273174+5828328, ARP 310, ARP 311, ARP 311 NED01, ARP 311 NED04, ARP310, ARP311, ASK 020813.0, ASK 020821.0, CGCG 1726.5+5833, CGCG 1726.6+5835, CGCG 1726.7+5832, CGCG 300-029, CGCG 300-030, CGCG 300-032, FLS26(R) J172717.3+582905, FLS26(R) J172731.7+582831, GALEXASC J172717.27+582906.2 , GALEXASC J172731.96+582833.6 , GALEXMSC J172717.47+582908.8 , GALEXMSC J172731.83+582833.9 , HDCE 1006 NED002, IC 1258, IC 1259, IC 1260, IC1258, IC1259, IC1260, KPG 517, LDCE 1253 NED006, MCG +10-25-035, MCG +10-25-040, Mr18:[BFW2006] 05541 NED09, Mr18:[BFW2006] 05541 NED11, Mr19:[BFW2006] 10818 NED09, Mr19:[BFW2006] 10818 NED10, Mr20:[BFW2006] 18447 NED02, NPM1G +58.0200, NSA 004814, NSA 004820, PGC 060320, PGC 060324, SDSS J172717.37+582907.9, SDSS J172717.38+582907.6, SDSS J172717.39+582907.7, SDSS J172731.71+582833.0, SDSS J172731.71+582833.1, SDSS J172731.71+582833.3, SDSS J172731.72+582833.0, SSTXFLS J172717.2+582907, SSTXFLS J172731.7+582833, UGC 10867, UGC 10869, UZC J172717.5+582907, VV 101, WBL 640, WBL 640-002, WBL 640-003, WBL 640-004, WN B1726+5833, XFLS160 J172717.1+582900, [BFW2006] J261.82242+58.48553 , [BFW2006] J261.88212+58.47592 , [FMS2006a] J172717.25+582907.5, [FMS2006a] J172731.71+582833.0, [MFA2007] 669,