Omicron Velorum (ο Vel, ο Velorum) is a

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Vela. It is the brightest member of the loose naked eye open cluster

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. Th ...

, also known as the ο Velorum Cluster. OmicronVelLightCurve

Omicron Velorum is a blue-white B-type star with a mean apparent magnitude of +3.60. It is probably a

main sequence In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...

object, but has also been classified as a subgiant or giant. It is approximately 495 light years from Earth. A slowly pulsating B star, it ranges between magnitudes 3.57 and 3.63 over 2.8 days. The correct

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

for ο Velorum has been debated. Lacaille assigned one Greek letter sequence for the bright stars of Argo Navis. These Lacaille designations are now shared across the three modern constellations of Carina,

Puppis Puppis is a constellation in the southern sky. Puppis, the Latin translation of "poop deck", was originally part of an over-large constellation Argo Navis (the ship of Jason and the Argonauts), which centuries after its initial description, was ...

, and Vela so that the same Greek letter is not usually found in more than one of the three. However, ο (omicron) is commonly used for stars in both Vela and

. Some authors contend that Lacaille actually assigned a Latin lower case 'o' to this star, while others suggest that ο Puppis should actually be a lower case 'o'. In the ''Coelum Australe Stelliferum'' itself, this star is labelled ο (omicron) Argus (du Navire in the French edition), while ο Puppis is labelled (Latin) o Argus in puppi (Pouppe du Navire in the French edition).

References

{{DEFAULTSORT:Omicron Velorum Velorum, Omicron B-type main-sequence stars 074195 042536 Slowly pulsating B stars Vela (constellation) 3447 PD-52 01583