NGC 5460 is an

open 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 constellation Centaurus. It is a bright but loose cluster of intermediate age located approximately 2,300 light years away from Earth. It is located nearly 2 degrees east-southeast of

Zeta Centauri Zeta Centauri, Latinized from ζ Centauri, is a binary star system in the southern constellation of Centaurus. It has the proper name Alnair , from the Arabic ''Nayyir Baṭan Qanṭūris'' (نير بطن قنطورس), meaning "The B ...

Observation history

NGC 5460 was discovered by James Dunlop in 1826. He described it on May 7, 1826 as "a curiously curved line of small stars, of nearly equal magnitudes; two stars of 7th magnitude to the east" and added it to his catalog as number 431.

John Herschel Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical wor ...

described as "a region of large bright stars of 8, 9... etc. magnitude; a very coarse cluster" and added it to General Catalogue as No. 3555. In the

New General Catalogue The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and ...

it is described as "very large, very little concentrated, stars 8th magnitude and fainter".

Characteristics

NGC 5460 is a loose open cluster, of Trumpler type II3m. There are 272 probable member stars within the angular radius of the cluster and 96 within the central part of the cluster. The tidal radius of the cluster is 4.1 - 8.2 parsecs (13 - 26 light years) and represents the average outer limit of NGC 5460, beyond which a star is unlikely to remain gravitationally bound to the cluster core. A photometric study by Barrado and Byrne in 1995 studied 353 stars near the core of the cluster and identified 25 members and 27 possible members. They estimated the age of the cluster to be 110 mys and its distance to be 740 pc and identified three stars, members and possible members, as

variable Variable may refer to: * Variable (computer science), a symbolic name associated with a value and whose associated value may be changed * Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many ...

. A spectrographic study of the cluster by Fossati et al. (2011) estimated the distance of the cluster to be 720 ± 50 pc, its age log t=8.2 ± 0.1 and the mean radial velocity −17.9 ± 5.2 km/s. The

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 ...

of the cluster is slightly higher than the solar one (Z = 0.013). The brightest of the members is HD 123226 (mag. 8.98, B8), which is also the hottest star of the cluster. One more star, HD 122983, (mag. 9.77, B9.5IV/V) has been found to be variable, with period 3.4 days. It is a He-weak star. Other chemically peculiar stars within the cluster are HD 123182 (He-weak star of an unclear type, mag. 9.88, spectral type B9), and UCAC 11105038 (mag. 11.59, A8). Also, the hotter component of the HD 123225 system may be an HgMn star.

References

External links

{{DEFAULTSORT:NGC 5460 5460 Centaurus Open clusters