|Observation data (J2000.0 epoch)|
|Right ascension||07h 24m 53s|
|Declination||−31° 52′ 23″|
|Distance||1,226 ly (376 pc)|
|Apparent magnitude (V)||3.5|
|Apparent dimensions (V)||60′|
|Estimated age||20 million years|
Collinder 140 is a nearby open cluster of stars in the constellation Canis 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. 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.
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, 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, and may have been created from the same interstellar cloud that formed NGC 2516 and NGC 2547.
- The Astronomical Almanac, Nautical Almanac Office, Great Britain: United States Naval Observatory, p. H68
- van Leeuwen, F. (April 2009), "Parallaxes and proper motions for 20 open clusters as based on the new Hipparcos catalogue", Astronomy and Astrophysics, 497 (1): 209–242, arXiv:0902.1039, Bibcode:2009A&A...497..209V, doi:10.1051/0004-6361/200811382
- "C 0722-321 -- Cluster of Stars", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2010-12-23
- Fitzgerald, M. P.; Miller, M.; Harris, G. L. H. (April 1980), "A spectroscopic and statistical study of Collinder 140", Monthly Notices of the Royal Astronomical Society, 191: 95–114, Bibcode:1980MNRAS.191...95F, doi:10.1093/mnras/191.1.95
- Plotner, Tammy (2007), What's Up 2007: 365 Days of Skywatching, Lulu.com, p. 87, ISBN 0-9782214-0-0
- Subramaniam, A.; Bhatt, H. C. (December 1999), "Star Formation History of the Puppis-Vela Region Using HIPPARCOS Data", in Nakamoto, T., Star Formation 1999, Proceedings of Star Formation 1999, pp. 373–374, Bibcode:1999sf99.proc..373S