One of the most beautiful images ever taken by the Hubble Space Telescope is the Sombrero Galaxy; also known as M104 or NGC 4594. This is an unbarred spiral galaxy located in the constellation of Virgo about 29 million light-years away.
Some of the defining features of the Sombrero Galaxy are its bright nucleus, large central bulge, and a prominent dust lane in its disk. The galaxy is seen nearly edge on, and so it has the appearance of a Sombrero hat. Since the galaxy has an apparent magnitude of +9.0, it’s easily visible in amateur telescopes; but too dim to see with the unaided eye.
The dark dust lane that you can see in the Hubble image is a symmetric ring that encloses the bulge of the galaxy. Astronomers have detected that it mostly contains hydrogen gas and dust. The bulk of star formation that occurs in the Sombrero Galaxy is happening within this ring.
As with our own Milky Way, astronomers have detected a supermassive black hole at the heart of the Sombrero Galaxy. Based on the speed of the stars orbiting around it, astronomers have calculated that it must have a mass of at least 1 billion suns. This is one of the most massive black holes detected in nearby galaxies.
If you want to look for the Sombrero Galaxy yourself, you’ll need good pair of 7×35 binoculars or a 4-inch telescope. The galaxy is located 11.5 degrees West of the star Spica, and 5.5 degrees northeast of Eta Corvi. With a medium sized telescope you can distinguish the bulge from the disk, and with a large telescope you should be able to see the dark dust lane.
We have written many articles about galaxies for Universe Today. Here’s an article about how the Sombrero Galaxy was imaged in three different wavelengths, and by three different observatories.
We have also recorded an episode of Astronomy Cast about galaxies – Episode 97: Galaxies.