NGC 428’s spiral structure is distorted and warped, thought to be a result of a collision between two galaxies, and it is still responsible for a healthy amount of star formation — another telltale sign of two galaxies combining.
European Space Agency writes:
NGC 428 was discovered by William Herschel in December 1786. More recently a type of supernova designated SN2013ct was discovered within the galaxy by Stuart Parker of the BOSS (Backyard Observatory Supernova Search) project in Australia and New Zealand, although it is unfortunately not visible in this image.
