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Astr110 Photography Projects, Fall 2007

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M30 Globular Cluster, Amber Reenders

Globular Cluster

The above picture is a Globular Cluster, which is a tight, spherical collection of as many as several hundred thousand stars. The first Globular Cluster was discovered by Abraham Ihle in 1665. The distinctive appearance of Globular Clusters makes them very easy to identify from far away. The total number of Globular Clusters that have been identified make up approximately two thirds to three fourths of the total number in the Milky Way. There are currently 151 Globular Clusters identified, but more are just waiting to be discovered! The reason there are still Globular Clusters that remain to be discovered is because it is nearly impossible to see directly in the center of the Milky Way due to it being very foggy. There is an estimated 10-20 remaining Globular Clusters yet to be discovered. Globular Clusters can be disrupted by stars escaping as they get randomly accelerated in mutual encounters, and by tidal forces from the parent galaxy acting upon them.

This particular Globular Cluster is approximately 87,400 Light Years away and has an angular size of 273". We can use the small angle formula to conlude that the linear distance of this object is approximately 116 Light Years across. Some interesting facts about this Globular Cluster are that the stars clump at a particular center while other stars slowly disperse outward causing a shattered affect. The blue stars in the picture are much hotter than the yellow stars. This is a very beautiful cluster because of its distinct center cluster of starts. Globular Clusters are just one of the many ways God reveals his creativity to us.

Fix, John D. Astronomy, Journey To The Cosmic Frontier. 4th ed. New York: McGraw-Hill, 2006.

Frommert , Hartmut . Globular Star Clusters. Ed. Christine Kronberg . 21 Aug. 2007. 6 Nov. 2007 <http://seds.org/messier/glob.html>.

Right Ascension (J2000) 21:40:24
Declination (J2000) -23:08:54
Filters used blue(B), green(V), red(R), and clear(C)
Exposure time per filter 3.0 seconds in red(R), clear(C), green(V), blue(B)
Date observed

October 22, 2007