Arp 258 is in the class Irregular Clumps. The Atlas note says "resolution
into knots on larger galaxy". It would be easy to debate the number of
galaxies versus galaxy fragments in this object. In the UGC, the
southeastern galaxy is 2140A and the irregular northern object is UGC 2140.
UGC 2140A is Hickson 18A, while UGC 2140 is broken up into 18B, C, and D in the
Hickson catalog. The two tiny galaxies just west of the southern tip of
UGC 2140 do not show up at all in NED but they do have Mitchell Anonymous
|10-inch Newtonian, StarlightXpress MX716, 23 minutes|