Messier 77 (NGC 1068)
It's hard to get your head around 100 billion stars in our own galaxy, never mind the huge distances between us and the nearest of stars, but when we look at other galaxies, we are often looking at spiral galaxies, not so dissimilar, and sometimes very different from our own, millions of light years from Earth, but containing billions upon billions of stars.
M77 while looking similar to our Milky Way, is quite dramatically different. First of all it's size, estimated at over 300 billion stars, is one of the largest galaxies in the Messier catalogue.
At the centre an active galactic nucleus of Seyfert 2 type, or put another way, a supermassive black hole so active, the accretion disk glow is extremely prominent (the largest of which we would call a Quasar), and some of these can shine so brightly, they outshine the entire galaxy.
At the outer edges of the galaxy, star formation is very active, there's a lot of hot clusters of bright blue giant stars (showing as blue/pink) scattered along strongly defined dust and gas lanes on each arm.
The galaxy can be found in the constellation of Cetus, and is 47 million light years from Earth.
