Collinder 140 is a nearby open cluster of stars in the constellationCanis Major. It was first catalogued in 1751 by the French astronomer Nicolas Louis de Lacaille, who described it as a "nebulous star cluster". It was catalogued again by the Swedish astronomer Per Collinder in 1931.[5] Fitzgerald et al. (1980) describe it as "a young extended cluster" and note that it is not obviously a cluster and may instead be a mere grouping of stars that formed together.[4]
Based on the combined parallax measurements of nine cluster members, this cluster has an estimated parallax of 2.66 ± 0.13 mas, which is equivalent to a distance modulus of 7.88 ± 0.11,[2] or a distance of 1,226 light-years (376 pc). The cluster has a density of 0.21 solar masses per cubic parsec; roughly double the density of stars near the Sun. It is about 20 million years old,[4] and may have been created from the same interstellar cloud that formed NGC 2516 and NGC 2547.[6]
^Subramaniam, A.; Bhatt, H. C. (December 1999), "Star Formation History of the Puppis-Vela Region Using HIPPARCOS Data", in Nakamoto, T. (ed.), Star Formation 1999, Proceedings of Star Formation 1999, pp. 373–374, Bibcode:1999sf99.proc..373S