Images by Date
Images by Category
Solar System
Stars
White Dwarfs
Supernovas
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Quasars
Galaxy Clusters
Cosmology/Deep Field
Miscellaneous
Images by Interest
Space Scoop for Kids
Multiwavelength
Sky Map
Constellations
3D Wall
Photo Blog
Top Rated Images
Image Handouts
Desktops
High Res Prints
Fits Files
Image Tutorials
Photo Album Tutorial
False Color
Cosmic Distance
Look-Back Time
Scale & Distance
Angular Measurement
Images & Processing
AVM/Metadata
Getting Hard Copies
Image Use Policy
Web Shortcuts
Chandra Blog
RSS Feed
Chandra Mobile
Chronicle
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
M31 Animations
Click for low-resolution animation
Tour of M31
Quicktime MPEG
Many consider Andromeda, also known as Messier 31, to be a sister galaxy to our own Milky Way. At a distance of only 2.5 million light years away, Andromeda is relatively close to our Galaxy. It is also a spiral galaxy like the Milky Way, and has many similar characteristics. However, a new study using data from NASA's Chandra X-ray Observatory has pointed out some interesting differences between these two galaxies when it comes to black holes. After combining over 150 Chandra observations spread over 13 years, researchers discovered 26 new black hole candidates in Andromeda. This is largest number to date found in a galaxy outside our own. Falling into the stellar-mass category, these black holes form when the most massive stars collapse. The result is a black hole that typically has between five and ten times the mass of the Sun. Seven of these black hole candidates are within 1,000 light years of Andromeda's center, more than what is found near the center of our Milky Way's core. This highlights that although Andromeda and the Milky Way are alike in many ways, they do have their differences. Astronomers have long known that the bulge of stars in Andromeda is bigger as is the super massive black hole at its center. Now we know that it may be a better producer of small black holes as well.
[Runtime: 01:45]

(Credit: NASA/CXC/J. DePasquale)




Return to M31 (June 12, 2013)