NGC 457, also known as the Owl Cluster or the ET Cluster, is an open star cluster in the constellation Cassiopeia. It lies about 7,900 light-years away from Earth and is estimated to be around 21 million years old. This cluster is notable for its distinctive shape, which resembles an owl with outstretched wings or a fictional alien with glowing eyes, hence the alternate name.
The most striking feature of NGC 457 is the two bright stars that represent the “eyes” of the owl. One of these stars is Phi Cassiopeiae, a supergiant over 16,000 times brighter than our Sun. The other is a foreground star, closer to Earth, but from our perspective, they appear together. Surrounding these eyes are over a hundred fainter stars that form the “wings” and “body,” giving the cluster its unique look.
Open clusters like NGC 457 are groups of stars that form from the same molecular cloud and are loosely bound by gravity. These stars are relatively young, making them good subjects for studying star formation and evolution. Unlike globular clusters, which are tightly packed and older, open clusters tend to disperse over time as their stars drift apart.
Astronomers and stargazers appreciate NGC 457 for its visual appeal, especially through small telescopes. Its bright, eye-like stars and wing-shaped formation make it a favorite target during autumn nights in the Northern Hemisphere. Observing clusters like NGC 457 helps us understand how stars form and evolve, and they provide a stunning reminder of the diverse beauty of our galaxy.
Capture Details:
Telescope: Celestron Nexstar 8se
Reducer/Flattener: Celestron .63x Reducer/Flattener
Filter: Optolong L-Pro
Camera: ZWO ASI294 MC Pro
Mount: Skywatcher EQM-35 Pro
Total Time: 2 hours 6 minutes
Capture Software: N.I.N.A.
Guiding: PHD2, ZWO asi120mm mini, ZWO OAG-L
Processed in: PixInsight
Additional details on Astrobin.com.