NGC 2516 (also known as Caldwell 96) is an
open star cluster
An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
in the southern sky in the constellation
Carina
Carina may refer to:
Places
Australia
* Carina, Queensland, a suburb in Brisbane
* Carina Heights, Queensland, a suburb in Brisbane
* Carina, Victoria, a locality in Mildura
Serbia
* Carina, Osečina, a village in the Kolubara District
...
discovered by
Abbe Lacaille
Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a French astronomer and geodesist who named 14 out of the 88 constellations. From 1750 to 1754, he studied the sky at the Cape of Goo ...
in 1751-1752. It is also called Southern Beehive or the Sprinter.
Description
This bright cluster itself is easily visible with the naked eye as a hazy patch, but is resolvable into stars using binoculars. It contains two 5th magnitude
red giant stars and three main
visual double stars: HJ 4027, HJ 4031 and I 29. A small
telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...
would be required to split the double stars, which are all pairs of 8-9 magnitude and 1-10 arcseconds separation.
NGC 2516 and the recently discovered nearby
star cluster
Star clusters are large groups of stars. Two main types of star clusters can be distinguished: globular clusters are tight groups of ten thousand to millions of old stars which are gravitationally bound, while open clusters are more loosely clust ...
Mamajek 2 in
Ophiuchus
Ophiuchus () is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek (), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constella ...
have similar age and
metallicity
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...
. Recently, kinematic evidence was presented by E. Jilinski and coauthors that suggests that these two stellar groups may have formed in the same star-forming complex some 135 million years ago.
The cluster is surrounded by the 500-parsec diameter halo consisting of stars ejected from cluster.
References
Bibliography
*
Burnham, Robert. ''Burnham's Celestial Handbook''. Dover, 1978. .
External links
*
SEDS– NGC 2516
{{Carina (constellation)
2516
Open clusters
Carina (constellation)
096b