Astr112 Photography Projects, Spring 2005

Intergalactic Wanderer, Tom Mazanec

One of the farthest objects still gravitationally bound to our Milky Way Galaxy, the Intergalactic Wanderer (a.k.a. Intergalactic Tramp and NGC 2419) is a globular star cluster located about 300,000 lightyears from the Earth. Globular clusters, typically spherical in shape, are old, relatively dense groups of stars (almost 1,000,000 stars in a space less than 400 lightyears across) that formed out of common material. This cluster was first discovered by William Herschel on December 31, 1788. For many years, astronomers doubted that the Intergalactic Wanderer was part of our Galaxy, but more recent calculations have proved that it is in a remote orbit.

This photograph was taken with a clear filter that is designed not to show color but to show in detail the hundreds of thousands of stars that are part of the Intergalactic Wanderer globular cluster. The star at the far right of the photograph is a single star located much closer to the earth, within the disk of our own galaxy, while the Intergalactic Wander, located 300,000 lightyears from us and made up of nearly a million stars, shows up nearly as bright in the night sky. Because it is so far from the Earth, it appears relatively small even though it is about 350 lightyears in diameter.

References:
-Freedman, Roger A. and William J. Kaufmann III. Universe Stars and Galaxies. W. H. Freeman & Co: New York, 2001.
-"Intergalactic Wanderer." Wikipedia, the free encyclopedia. 1 Feb 2005. http://en.wikipedia.org/wiki/Intergalactic_Wanderer