Constellation Vela Declination −53° 02′ Apparent magnitude (V) 2.5 | Right ascension 08 40.6 Distance (175 pc) Apparent dimensions (V) 50′ | |
IC 2391 (also known as the Omicron Velorum Cluster or Caldwell 85) is an open cluster in the constellation Vela. The Persian astronomer Al Sufi may have first described it about 964. It was found by Abbe Lacaille and cataloged as Lac II 5.
The cluster is about 500 light-years away from Earth and can be seen with the naked eye. It contains about 30 stars with a total visual magnitude of 2.5, spread out along 50 arcminutes. The cluster appears to be about the same age as the open cluster IC 2602, and has a lithium depletion boundary age of about 50 million years.
References
IC 2391 Wikipedia(Text) CC BY-SA