Pinwheel Galaxy (M33) in Triangulum constellation is our neighbor. It is the second nearest galaxy to our Milky way (excluding our Milky Way’s satellites). It’s smaller than our galaxy – only about 40 billion stars (as compared to about 400 billion stars for Milky Way). This galaxy is about 2.4 to 3 million light years away and is not too far from the Andromeda Galaxy, to which, it may be bound gravitationally.
Unlike the Milky Way and Andromeda galaxies, the Triangulum Galaxy does not appear to have a supermassive black hole at its center.
In this picture, you can see stars of that galaxies that are really small blue dots, and pink nebulae.
There are many other stars in this image, which are stars of our own galaxy and they just happen to exist in the line of sight to the Pinwheel Galaxy. In other words, all stars that are not small blue dots in this image, belong to Milky Way. On the other hand, all small blue dots are hot young stars that we are able to see individually, even though these stars are 2.5+ million light years away!
All pink regions are nebulae on that galaxy. These hydrogen clouds are the areas where thousands of new stars are being formed. The brownish bands near the core of the galaxy are dust bands that are made of really small dust particles.
For this image, I had to take 4 different panels and merge them using Maxim DL Mosaic tool. Exposure time – 26 hours (31 luminance images of 10 minutes, 9 each RGB images of 3 minutes each for each panel).