Leo Triplett (M 65, M 66, NGC 3628)
The Leo Triplett consists of the three spiral galaxies M 66, M 65 and NGC 3628. It is also known as M 66 group. It is 36 million light-years away.
The galaxy NGC 3628 is maybe one of the most interesting bright galaxies.
One striking artefact associated with this galaxy is a long tidal star tail some 300,000 light-years long. NGC 3628 is about 160,000 light-years long. Probably the tail consists of stars that were torn of the galaxy when a small dwarf galaxy passed or when a close encounter of NGC 3628 and M 66 took place.
The mass of the tail is about 15% of that of the large galaxy, it’s surface brightness is about 26,5mag/arcsec^2. The stars in tail have an age of several hundred million years – corresponding to an close encounter of NGC 3628 and M 66 about 800 million years ago.
In 2014, a tidal dwarf galaxy was discovered at the end of the tail.