Globular cluster in the constellation of Sagittarius
NGC 6522 is aglobular cluster of stars in the southernconstellation ofSagittarius . It was discovered by German-British astronomerWilliam Herschel on June 24, 1784. The cluster has anapparent visual magnitude of 8.3 and anangular diameter of[ 3] kly (7.7 kpc ) from the Sun,[ 2] Milky Way's central bulge ,[ 7] Galactic Center .[ 1] Baade's Window .[ 8] reddening due tointerstellar dust and the view is heavily contaminated byfield stars , making it more difficult to identify members.[ 9]
NGC 6522 is possibly the oldest star cluster in theMilky Way ,[ 10] [ 11] [ 12] core collapsed cluster with acore radius of[ 9] [ 13]
This is a low mass globular cluster with an estimated× 104 mass of the Sun . Distinctive chemical abundances among the members indicate the cluster has multiple populations of stars, with the younger populations exhibiting pollution from earlier generations.[ 4] variable stars have been identified as members of NGC 6522, consisting of eightRR Lyrae , threetype II Cepheids , and ninelong-period variable stars .[ 9] pulsars have been discovered.[ 14]
The globular clusters
NGC 6528 (lower left) is close to NGC 6522 (upper right)
^a b c d Di Criscienzo, M.; et al. (February 2006)."RR Lyrae-based calibration of the Globular Cluster Luminosity Function" .Monthly Notices of the Royal Astronomical Society .365 (4):1357– 1366.arXiv :astro-ph/0511128 Bibcode :2006MNRAS.365.1357D .doi :10.1111/j.1365-2966.2005.09819.x S2CID 17838243 . ^a b c Boyles, J.; et al. (November 2011). "Young Radio Pulsars in Galactic Globular Clusters".The Astrophysical Journal .742 (1): 51.arXiv :1108.4402 Bibcode :2011ApJ...742...51B .doi :10.1088/0004-637X/742/1/51 .S2CID 118649860 . ^a b c O'Meara, Stephen James (2013).Deep-Sky Companions: Southern Gems ISBN 9781107015012 ^a b Fernández-Trincado, J. G.; et al. (July 2019). "H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia".Astronomy & Astrophysics .627 . id. A178.arXiv :1801.07136 Bibcode :2019A&A...627A.178F .doi :10.1051/0004-6361/201834391 . ^ Koleva, M.; et al. (April 2008)."Spectroscopic ages and metallicities of stellar populations: validation of full spectrum fitting" .Monthly Notices of the Royal Astronomical Society 385 (4):1998– 2010.arXiv :0801.0871 Bibcode :2008MNRAS.385.1998K .doi :10.1111/j.1365-2966.2008.12908.x S2CID 17571531 . ^ "SIMBAD Astronomical Database" .Results for NGC 6522 . Retrieved2011-03-13 .^ Ness, Melissa; et al. (December 2014)."NGC 6522: a typical globular cluster in the Galactic bulge without signatures of rapidly rotating Population III stars" .Monthly Notices of the Royal Astronomical Society .445 (3): 2994−2998.arXiv :1408.0290 Bibcode :2014MNRAS.445.2994N .doi :10.1093/mnras/stu2144 ^ "NGC 6522" .Students for the Exploration and Development of Space . Retrieved2020-09-23 .^a b c Arellano Ferro, A.; et al. (October 2023). "Variable stars in the field of the Galactic bulge globular cluster NGC 6522".Astrophysics and Space Science .368 (10). id. 91.arXiv :2310.16257 Bibcode :2023Ap&SS.368...91A .doi :10.1007/s10509-023-04249-4 . ^ Barbuy, B.; et al. (November 2009). "VLT-FLAMES Analysis of 8 giants in the Bulge Metal-poor Globular Cluster NGC 6522: Oldest Cluster in the Galaxy?".Astronomy and Astrophysics .507 (1):405– 415.arXiv :0908.3603 Bibcode :2009A&A...507..405B .doi :10.1051/0004-6361/200912748 . ^ Shiga, David (30 April 2011)."The universe's first stars were whirling dervishes" .New Scientist . Retrieved2024-09-09 . ^ Chiappini, Cristina; et al. (28 April 2011). "Imprints of fast-rotating massive stars in the Galactic Bulge".Nature .472 (7344):454– 457.Bibcode :2011Natur.472..454C .doi :10.1038/nature10000 .PMID 21525928 . ^ Barbuy, B.; et al. (October 2021). "UVES analysis of red giants in the bulge globular cluster NGC 6522".Astronomy & Astrophysics .654 . id. A29.arXiv :2107.08746 Bibcode :2021A&A...654A..29B .doi :10.1051/0004-6361/202140815 . ^ Abbate, F.; et al. (December 2023). "A MeerKAT view of the pulsars in the globular cluster NGC 6522".Astronomy & Astrophysics .680 . id. A47.arXiv :2310.03800 Bibcode :2023A&A...680A..47A .doi :10.1051/0004-6361/202347725 .
6001 to 6100 6101 to 6200 6201 to 6300 6301 to 6400 6401 to 6500 6501 to 6600 6601 to 6700 6701 to 6800 6801 to 6900 6901 to 7000
Media related toNGC 6522 at Wikimedia Commons