DescriptionImages

Object name: ARP286

Designation(s): ARP286, NGC5560, NGC5566, NGC5569,

Arp 286 consists of three galaxies, NGC 5560, NGC 5566 and NGC 5569 right to left in my image. They are in the constellation of Virgo about 80 to 90 light-years distant. Arp put them in his category: Galaxy groups: Infall and attraction. This likely refers to NGC 5560 and NGC 5566 as NGC 5560 appears warped and drawn out by the gravity of NGC 5566. NGC 5566 itself seems distorted. The outer "arms" look more like plumes and are somewhat unsymmetrical. Also, the northern one has a prominent reddish dust lane that's hard to explain other than by tidal effects. Also, I think its disk appears slightly warped as well. Arp's comment on this entry reads: "Connection not visible." I see no tidal star streams connecting any of the three, though there is a faint plume coming off the south end of NGC 5566 heading to NGC 5560. A much longer exposure might show a connection. NGC 5569 seems unfazed and likely is more a line of sight member that appears far closer to the other two than is really the case.

NGC 5660 was discovered by William Hershel on May 15, 1787. It is in the second Herschel 400 program. He found NGC 5569 3 years earlier on March 19, 1784. NGC 5666 was discovered by John Herschel on May 9, 1825.

NGC 5560 is classed at NED as SB(s)b pec and has a redshift distance of about 90 million light-years. NGC 5566 is classed as SB(r)ab and is a LINER galaxy. Redshift data puts it at about 80 million light-years. Tully-Fisher measurements put it at about 86 million light-years. Certainly, it and NGC 5560 are likely quite close whichever measurement you choose. NGC 5569 is classed as SAB(rs)cd. By redshift, it is a bit over 90 million light-years distant though one Tully-Fisher measurement puts it far closer at about 57 million light-years. I doubt this measurement as it involves rotational velocity measurements that are difficult with near face on galaxies. There appears to be a 4th member of the group in the image. A dwarf galaxy at the very top of my image a bit left of center has a redshift distance of 90 million light-years.

NED has distance data on only a few of the galaxies in my image. I've made an annotated image showing these. The field is rather rich in distant quasars.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp286.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME