NGC 6541 (also known as Caldwell 78) is a globular cluster of stars in the southern constellation of Corona Australis. The globular cluster was discovered by Niccolò Cacciatore at the Palermo Astronomical Observatory, Sicily, on March 19, 1826. It was independently found by James Dunlop on July 3, 1826. The cluster has an apparent visual magnitude of 6.3 and an angular diameter of 15′. It is visible with binoculars or a small telescope.[4]
Located at a distance of 24.8 kly (7.6 kpc) from the Sun,[3] it is orbiting within the central region of the Milky Way about 7.2 kly (2.2 kpc) from the Galactic Center.[8] It is considered a metal-poor inner halo cluster, being the third most metal-poor globular cluster within 9.8 kly (3 kpc) of the center.[8] The cluster has 5.72×105 times the mass of the Sun.[5] It is estimated to be around 12.9 billion years old,[6] and is believed to have undergone core collapse.[8] A total of 94 blue straggler members have been identified,[9] as well as three W Ursae Majoris and nine SX Phoenicis variables.[10]
References
↑Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin849 (849): 11–14, Bibcode: 1927BHarO.849...11S.
↑ 2.02.1Goldsbury, Ryan et al. (December 2010), "The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters", The Astronomical Journal140 (6): 1830–1837, doi:10.1088/0004-6256/140/6/1830, Bibcode: 2010AJ....140.1830G.
↑ 3.03.1Baumgardt, H.; Vasiliev, E. (August 2021), "Accurate distances to Galactic globular clusters through a combination of Gaia EDR3, HST, and literature data", Monthly Notices of the Royal Astronomical Society505 (4): 5957–5977, doi:10.1093/mnras/stab1474, Bibcode: 2021MNRAS.505.5957B.
↑ 8.08.18.2Lee, Jae-Woo; Carney, Bruce W. (November 2006), "VI Photometry of Globular Clusters NGC 6293 and NGC 6541: The Formation of the Metal-poor Inner Halo Globular Clusters", The Astronomical Journal132 (5): 2171–2186, doi:10.1086/507412, Bibcode: 2006AJ....132.2171L.
↑Raso, S. et al. (2017), "The "UV-route" to Search for Blue Straggler Stars in Globular Clusters: First Results from theHSTUV Legacy Survey", The Astrophysical Journal839 (1): 64, doi:10.3847/1538-4357/aa6891, Bibcode: 2017ApJ...839...64R.