APOD 3.1

January 20th, 2011.                        The Once and Future Stars of Andromeda

Queen Andromeda was a very interesting constellation in our class since she had many unique features, including her Worm like appearance, her notable star Mira, and her circumpolar feature that allows for the constellation to remain above the horizon 24 hours a day.  Additionally, the constellation contains M31, which we did not talk much about and I hoped to learn of from this APOD.  M31, or the Andromeda Galaxy, is a spiral galaxy located 2.5 million light-years away.  This picture was taken by two satellites, Herschel and XMM-Newton, in a combination of infrared and X-Ray spectrum. The rings of dust contain gaseous reservoirs where many new stars are being formed, however towards the center core, some of the more predominant starts are shown to be coming to the end of their lives.  Not clearly shown in the picture however, is the true size of this great Andromeda Galaxy.  Over twice the size of our own Milky Way, the galaxy stretches over 200,000 light-years across and contains thousands of stars.