ic 2391とは 意味・読み方・使い方

IC 2391 (also known as the Omicron Velorum Cluster) is an open cluster in the constellation Vela. It has been purported to be first described by the Persian astronomer Al Sufi in about 964. It was also found by Abbe Lacaille and has been cataloged as Lac II 5. The cluster is at a distance of about 500 light-years away from Earth and can be seen with the naked eye. The cluster has a total visual magnitude of 2.5. The open cluster spans an area of sky of about 50 arcminutes, and contains about 30 stars. The cluster might be about the same age as the open cluster IC 2602, and have a lithium depletion boundary age of about 50 million years old.