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Snowflake Cluster (NGC 2264)
Eunsub Cho

Christmas Tree Nebula/Snowflake Cluster

NGC 2264 is the name referring to a region composed of four set of astronomical objects: the Cone Nebula, the Christmas Cluster, the Snowflake Cluster, and the Fox Fur Nebula. The picture above is specifically centered on the Snowflake Cluster. It is an open cluster of stars that contains over thousands of stars that lie about the same distance away from the Earth. As most open clusters, these stars most likely would have formed at relatively close span of time. Usually, group of stars such as the Snowflake cluster are birthed by the collapsing of the interstellar cloud of hydrogen and helium gases. As gravity continues to cause the gas cloud to collapse, the temperature and pressure increase in that region. This forms what are called protostars, newborn seed-stars that develop into stars when the temperature builds to the point when hydrogen fusion becomes possible. In case of NGC 2264, scientists believe that it is a group of protostars (about 100,000 years old) that formed in steady intervals in a shape resembling a wheel or a snowflake: hence the nickname, “Snowflake Cluster.”

The picture reveals clearly the dust particles reflecting the light as a bluish foggy structure surrounding the stars. The dust particles, however, are most likely behind the stars relative to our vantage point, which is reflecting the light from the stars back towards us in bluish color. Around the middle of the rightside of the picture, there are two black blobs in contrast to the dark blue background. This is dust particles that are in the foreground that are blocking the reflected star lights from the background to reach us. On the other hand, the comparatively purplish color of the cloud around the stars in the bottom right corner indicate remaining hydrogen gas which emits reddish light; the gas is probably left from the original interstellar gas cloud of the nebula. Concerning distance, the object is estimated to be 2700 light years away; we find a maximum angular size of 1230 arc seconds, which corresponds to a linear size of 16 light years.


Bennett, J., Donahue, M., Schneider, N., & Voit, M. (2002). Essential Cosmic Perspective (2nd ed.). Addison Wesley.

Smith, Y. (2008, March 23). NASA - Stellar Snowflake Cluster. Image Feature, . Retrieved April 17, 2011, from

The Spitzer Space Telescope. (2005). [Graph illustration and caption of NGC 2264 in the Infrared]. Retrieved from

Right Ascension (J2000) 06:41:06
Declination (J2000) +09:53:00
Filters used B (Blue), R (Red), V (Green)
Exposure time per filter B (120s x 5); V and R (60s x5)
Date observed March 25, 2011 UT



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