#PhotoOfTheDay: #UGC 1810: Wildly Interacting Galaxy from Hubble
The featured galaxy is labelled UGC 1810 by itself, but together with its collisional partner is known as Arp 273. The overall shape of UGC 1810 -- in particular its blue outer ring -- is likely a result of wild and violent gravitational interactions.
This ring's blue color is caused by massive stars that are blue hot and have formed only in the past few million years.