NGC 6250 is a open cluster of stars in the southern constellation of Ara, near the border with Scorpius.[5] It was discovered by English astronomer John Herschel on July 1, 1834.[6] This cluster has an apparent visual magnitude of 5.9 and spans an angular diameter of 18′,[2] with the brightest member being of magnitude 7.6. About 15 members are visible with binoculars or a small telescope.[7] NGC 6250 is located at a distance of 2,820 ly (865 pc) from the Sun,[1] and is approaching with a mean radial velocity of −10±6 km/s.[8]
The Trumpler classification of NGC 6250 is II 3 r, indicating a rich cluster of stars (r) with a slightly disparate grouping (II) and a large brightness range (3).[9] This is a young cluster with an estimated age of 14 million years.[3] Seven cluster members are B-type stars,[10] and three are illuminating reflection nebulae.[11] Two magnetic chemically peculiar stars (CP2) and two candidate Lambda Boötis stars have been identified as members.[9] The metallicity of the cluster members is consistent with the Sun.[8]
^ abBayer, C.; et al. (November 2000), "CCD photometric search for peculiar stars in open clusters. I. NGC 2169, Melotte 105 and NGC 6250", Astronomy and Astrophysics Supplement, 147: 99–109, Bibcode:2000A&AS..147...99B, doi:10.1051/aas:2000294.
^McSwain, M. Virginia; Gies, Douglas R. (November 2005), "The Evolutionary Status of Be Stars: Results from a Photometric Study of Southern Open Clusters", The Astrophysical Journal Supplement Series, 161 (1): 118–146, arXiv:astro-ph/0505032, Bibcode:2005ApJS..161..118M, doi:10.1086/432757.
^Herbst, W. (November 1977), "Extinction law in dust clouds and the young southern cluster NGC 6250: further evidence for high values of R", Astronomical Journal, 82: 902–907, Bibcode:1977AJ.....82..902H, doi:10.1086/112144.
Media related to NGC 6250 at Wikimedia Commons
