IC 2391

IC 2391
Observation data (J2000.0 epoch)
Constellation	Vela
Right ascension	08^h 40.6^m
Declination	−53° 02′
Distance	(175 pc)
Apparent magnitude (V)	2.5
Apparent dimensions (V)	50′
Physical characteristics
Other designations	C 0838-528, Caldwell 85

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,^[1] and has a lithium depletion boundary age of about 50 million years.^[2]

See also

• Omicron Velorum

References

1. Stauffer, J.R.; et al. (1997). "Rotational Velocities and Chromospheric/Coronal Activity of Low-Mass Stars in the Young Open Clusters IC 2391 and IC 2602". Astrophysical Journal 479 (2): 776. Bibcode:1997ApJ...479..776S. doi:10.1086/303930.
2. Barrado y Navascues, D., Stauffer, J.R., & Jayawardhana, R. (2002). "Spectroscopy of Very Low Mass Stars and Brown Dwarfs in IC 2391: Lithium Depletion and Hα Emission". Astrophysical Journal 614 (1): 386–397. arXiv:astro-ph/0406436. Bibcode:2004ApJ...614..386B. doi:10.1086/423485.

External links

• IC 2391 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
• SEDS: entry for IC 2391
• Atlas of the Universe: list of open clusters
• Simbad: entry for IC 2391

Coordinates: 08^h 40^m 18^s, −52° 54′ 60″