Messier 19 or M19 (also designated NGC 6273) is a globular cluster in the constellationOphiuchus. It was discovered by Charles Messier on June 5, 1764[6] and added to his catalogue of comet-like objects that same year. It was resolved into individual stars by William Herschel in 1784. His son, John Herschel, described it as "a superb cluster resolvable into countless stars".[7] The cluster is located 4.5° WSW of Theta Ophiuchi and is just visible as a fuzzy point of light using 50 mm (2.0 in) binoculars. Using a telescope with a 25.4 cm (10.0 in) aperture, the cluster shows an oval appearance with a 3′ × 4′ core and a 5′ × 7′ halo.[6]
M19 is one of the most oblate of the known globular clusters.[7] This flattening may not accurately reflect the physical shape of the cluster because the emitted light is being strongly absorbed along the eastern edge. This is the result of extinction caused by intervening gas and dust. When viewed in the infrared, the cluster shows almost no flattening.[8] It lies at a distance of about 28.7 kly (8.8 kpc) from the Solar System,[3] and is quite near to the Galactic Center at only about 6.5 kly (2.0 kpc) away.[9]
This cluster contains an estimated 1,100,000 times the mass of the Sun[3] and it is around 11.9 billion years old.[5] The stellar population includes four Cepheids and RV Tauri variables, plus at least one RR Lyrae variable for which a period is known.[10] Observations made during the ROSAT mission failed to reveal any low-intensity X-ray sources.[11]
^Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
^ abThompson, Robert Bruce; Thompson, Barbara Fritchman (2007), Illustrated Guide to Astronomical Wonders, Diy Science, O'Reilly Media, Inc., p. 331, ISBN978-0596526856.
^ abBurnham, Robert (1978), Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System, Dover Books on Astronomy, vol. 2 (2nd ed.), Courier Dover Publications, p. 1263, ISBN978-0486235684.
^van den Bergh, Sidney (May 2008), "The Flattening of Globular Clusters", The Astronomical Journal, 135 (5): 1731–1737, arXiv:0802.4061, Bibcode:2008AJ....135.1731V, doi:10.1088/0004-6256/135/5/1731, S2CID 250750083.
^Bica, E.; et al. (April 2006), "Globular cluster system and Milky Way properties revisited", Astronomy and Astrophysics, 450 (1): 105–115, arXiv:astro-ph/0511788, Bibcode:2006A&A...450..105B, doi:10.1051/0004-6361:20054351, S2CID 1559058.
^Clement, Christine M.; et al. (November 2001), "Variable Stars in Galactic Globular Clusters", The Astronomical Journal, 122 (5): 2587–2599, arXiv:astro-ph/0108024, Bibcode:2001AJ....122.2587C, doi:10.1086/323719, S2CID 38359010.
^Verbunt, F. (March 2001), "A census with ROSAT of low-luminosity X-ray sources in globular clusters", Astronomy and Astrophysics, 368: 137–159, arXiv:astro-ph/0012261, Bibcode:2001A&A...368..137V, doi:10.1051/0004-6361:20000469, S2CID 2442974.
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messier, also, designated, 6273, globular, cluster, constellation, ophiuchus, discovered, charles, messier, june, 1764, added, catalogue, comet, like, objects, that, same, year, resolved, into, individual, stars, william, herschel, 1784, john, herschel, descri. Messier 19 or M19 also designated NGC 6273 is a globular cluster in the constellation Ophiuchus It was discovered by Charles Messier on June 5 1764 6 and added to his catalogue of comet like objects that same year It was resolved into individual stars by William Herschel in 1784 His son John Herschel described it as a superb cluster resolvable into countless stars 7 The cluster is located 4 5 WSW of Theta Ophiuchi and is just visible as a fuzzy point of light using 50 mm 2 0 in binoculars Using a telescope with a 25 4 cm 10 0 in aperture the cluster shows an oval appearance with a 3 4 core and a 5 7 halo 6 Messier 19Globular cluster Messier 19 in OphiuchusObservation data J2000 epoch ClassVIII 1 ConstellationOphiuchusRight ascension17h 02m 37 69s 2 Declination 26 16 04 6 2 Distance28 7 kly 8 8 kpc 3 Apparent magnitude V 6 8 4 Apparent dimensions V 17 0 Physical characteristicsMass1 10 106 3 M Radius70 lyMetallicity Fe H displaystyle begin smallmatrix left ce Fe ce H right end smallmatrix 1 53 5 dexEstimated age11 90 Gyr 5 Other designationsNGC 6273 GCl 52 2 See also Globular cluster List of globular clustersM19 is one of the most oblate of the known globular clusters 7 This flattening may not accurately reflect the physical shape of the cluster because the emitted light is being strongly absorbed along the eastern edge This is the result of extinction caused by intervening gas and dust When viewed in the infrared the cluster shows almost no flattening 8 It lies at a distance of about 28 7 kly 8 8 kpc from the Solar System 3 and is quite near to the Galactic Center at only about 6 5 kly 2 0 kpc away 9 This cluster contains an estimated 1 100 000 times the mass of the Sun 3 and it is around 11 9 billion years old 5 The stellar population includes four Cepheids and RV Tauri variables plus at least one RR Lyrae variable for which a period is known 10 Observations made during the ROSAT mission failed to reveal any low intensity X ray sources 11 Map showing the location of M19See also editList of Messier objectsReferences edit Shapley Harlow Sawyer Helen B August 1927 A Classification of Globular Clusters Harvard College Observatory Bulletin 849 849 11 14 Bibcode 1927BHarO 849 11S a b c M 19 SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved 2006 11 16 a b c d 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 Messier 19 SEDS Messier Catalog Retrieved 28 April 2022 a b c Forbes Duncan A Bridges Terry May 2010 Accreted versus in situ Milky Way globular clusters Monthly Notices of the Royal Astronomical Society 404 3 1203 1214 arXiv 1001 4289 Bibcode 2010MNRAS 404 1203F doi 10 1111 j 1365 2966 2010 16373 x S2CID 51825384 a b Thompson Robert Bruce Thompson Barbara Fritchman 2007 Illustrated Guide to Astronomical Wonders Diy Science O Reilly Media Inc p 331 ISBN 978 0596526856 a b Burnham Robert 1978 Burnham s Celestial Handbook An Observer s Guide to the Universe Beyond the Solar System Dover Books on Astronomy vol 2 2nd ed Courier Dover Publications p 1263 ISBN 978 0486235684 van den Bergh Sidney May 2008 The Flattening of Globular Clusters The Astronomical Journal 135 5 1731 1737 arXiv 0802 4061 Bibcode 2008AJ 135 1731V doi 10 1088 0004 6256 135 5 1731 S2CID 250750083 Bica E et al April 2006 Globular cluster system and Milky Way properties revisited Astronomy and Astrophysics 450 1 105 115 arXiv astro ph 0511788 Bibcode 2006A amp A 450 105B doi 10 1051 0004 6361 20054351 S2CID 1559058 Clement Christine M et al November 2001 Variable Stars in Galactic Globular Clusters The Astronomical Journal 122 5 2587 2599 arXiv astro ph 0108024 Bibcode 2001AJ 122 2587C doi 10 1086 323719 S2CID 38359010 Verbunt F March 2001 A census with ROSAT of low luminosity X ray sources in globular clusters Astronomy and Astrophysics 368 137 159 arXiv astro ph 0012261 Bibcode 2001A amp A 368 137V doi 10 1051 0004 6361 20000469 S2CID 2442974 External links edit nbsp Wikimedia Commons has media related to Messier 19 Messier 19 SEDS Messier pages Messier 19 Galactic Globular Clusters Database page Messier 19 on WikiSky DSS2 SDSS GALEX IRAS Hydrogen a X Ray Astrophoto Sky Map Articles and imagesPortals nbsp Astronomy nbsp Stars nbsp Outer space Retrieved from https en wikipedia org w index php title Messier 19 amp oldid 1192492502, wikipedia, wiki, book, books, library,
