Last week Teresa8 asked about the blue thing in this picture:588011503136145442
No its not a Voorwerp, but a hot blue star. But I noticed the star trails to NW/SE and zoomed out:
Now one can see several hot blue stars, and a pair of beautiful star trails extending from the galaxy. Star trails like this are indicative of interactions with another galaxy. Lets Zoom out a bit more:
There in the foreground are yet more hot blue stars - it is a nearby cluster of hot new stars. Looking to the South there are a pair of large galaxies.
Although none of these have SDSS spectra, NED has spectra for our spiral and the large elliptical to the South - which are virtually identical. Now I always say don't use redshift to find if galaxies are merging, but rather use it as a way of eliminating a merger if they are significantly different. Better clues for mergers are star trails (Yay), distortion, star forming, dual cores and common halos.
Our pretty spiral is interacting with at least one of the other galaxies to the south. So we have a star cluster and a galaxy cluster.