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Astr110 Photography Projects, Fall 2005

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E.T. Cluster NGC 457, Dustin Smith and Graham Howard

The Constellation Cassiopeia serves as home to many open clusters, including the NGC 457, an open star cluster - known by many names including the airplane cluster, the alien cluster, the ghost cluster and more - but known most commonly as the E.T. Cluster or the Owl Cluster after it's two bright stars that look like eyes. It was recognized as an owl much earlier than E.T. but the name caught on after the hit movie E.T. Some have also found two arms and two legs to connect to E.T.'s two eyes - but the above image only shows a partial bit of one arm. Cassiopeia was discovered by William Herschel in 1787, and has been recognized by many under many different names ever since.

This cluster is located about 9,000 LY from us and contains in the neighborhood of 200 stars. The above image which captures a portion of E.T. is approximately 21 LY across. Phi Cassiopeia, the largest and brightest star and E.T.'s right eye may or may not be a member of this cluster. Scientists do agree that it is a yellow super giant that has evolved through the red giant phase.

This cluster of Stars is classified as an open cluster and like all open clusters is found in the disk of the galaxy. These stars probably formed at the same time, and judging by the appearance of the stars and the colors present, this is a younger cluster. There are many blue stars in this cluster, this suggests that it is younger and hotter and still in the beginning stages of its lifecycle.


Bennett, Donahue, Schneider, Voit The Cosmic Perspective 2004 Pearson Education, Inc, San Francisco, CA.

Trusock, Tom Nov. 6, 2005 Small Wonders: Cassiopeia - retrieved Dec. 6, 2005
Cloudy Nights

Barlow, Bob. Sep. 2, 2004 Sky Watch - retrieved Nov. 30, 2005.
Dudley Observatory

March 13, 2004 - retrieved Nov. 30, 2005. 
retrieved Nov. 30, 2005

Right Ascension (J2000) 1 19:56
Declination (J2000) +58:16:00
Filters used blue(B), green(V), red(R), and clear(C)
Exposure time per filter 5x60 seconds in C, 300 seconds in BVR
Date observed

November 19, 2005 (B)
November 5, 2005, (VR)
November 8, 2005 (C)