Triplet in Leo

The Leo Triplet of Galaxies (also known as the M66 Group) is a small group of interacting galaxies about 35 million light-years away in the constellation Leo. This galaxy group consists of the spiral galaxies M65 (yellow one, top), M66 (blue one, bottom), and NGC 3628 (Hamburger galaxy left).

The three galaxies in the M66 Group have all been affected by gravitational interactions with each other. This is evident in the deformed, drawn out spiral arms of M66 that are experiencing a high rate
of star forming activity and in the warped, inflated disk of NGC 3628.

With a prominent tidal tail consisting mainly of young blue stars, NGC 3628 seems to be the most affected of the three, while M65 appears to
have suffered the least damage from the interaction. The tidal tail of NGC 3628 spans over 300,000 light years, but is very faint and can only just be seen here.

Messier 66, the largest and brightest member of the Leo Triplet, is roughly 95 light years across. Messier 65 is an intermediate spiral galaxy, poor in dust and gas, and shows little evidence of star formation.