IC 2391
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. It includes the following naked-eye members: IC 2391 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. IC 2391 has been closely linked to the Argus Association of co-moving stars. Proposed members of this moving group include Denebola, Epsilon Pavonis, 49 Ceti, HD 61005, and HD 88955.