This is UGC 12591. It’s an massive galaxy (about 4X that of the Milky Way) about 400 million light-year away. It’s form is not quite lenticular and not quite spiral, and it rotates very rapidly at speeds over 1,000,000 km/h. Astronomers are unsure whether the galaxy simply formed and grew slowly over time or whether it might have grown unusually massive by colliding and merging with another large galaxy at some point in its past.
Image Credit: NASA / ESA