[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/en\/wiki2\/messier-72-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/en\/wiki2\/messier-72-wikipedia\/","headline":"Messier 72 – Wikipedia","name":"Messier 72 – Wikipedia","description":"From Wikipedia, the free encyclopedia Globular cluster in the constellation Aquarius Wikimedia Commons has media related to Messier 72. Messier","datePublished":"2016-03-26","dateModified":"2016-03-26","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/en\/wiki2\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/en\/wiki2\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/4\/4a\/Commons-logo.svg\/30px-Commons-logo.svg.png","url":"https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/4\/4a\/Commons-logo.svg\/30px-Commons-logo.svg.png","height":"40","width":"30"},"url":"https:\/\/wiki.edu.vn\/en\/wiki2\/messier-72-wikipedia\/","wordCount":3001,"articleBody":"From Wikipedia, the free encyclopediaGlobular cluster in the constellation AquariusWikimedia Commons has media related to Messier 72.Messier 72 (also known as M72 or NGC 6981) is a globular cluster in the south west of the very mildly southern constellation of Aquarius.Observational history and guide[edit]M72 was discovered by astronomer Pierre M\u00e9chain in 1780.[a] His countryman Charles Messier looked for it 36 days later, and included it in his catalog.[8] Both opted for the then-dominant of the competing terms for such objects, considering it a faint nebula rather than a cluster. With a larger instrument, astronomer John Herschel called it a bright “cluster of stars of a round figure”. Astronomer Harlow Shapley noted a similarity to Messier 4 and 12.[9]It is visible in a good night sky as a faint nebula in a telescope with a 6\u00a0cm (2.4\u00a0in) aperture. The surrounding field stars become visible from a 15\u00a0cm (5.9\u00a0in)-aperture device. One of 25\u00a0cm (9.8\u00a0in) will allow measurement of an angular diameter of 2.5\u00a0\u2032. At 30\u00a0cm (12\u00a0in) the core is clear: its 1.25\u00a0\u2032 diameter, meaning a broad spread; and small parts scarcer in stars to the south and east.[10]Properties[edit]Based upon a 2011 census of variable stars, the cluster is 54.57\u00a0\u00b1\u00a01.17\u00a0kly (16.73\u00a0\u00b1\u00a00.36\u00a0kpc) away from the Sun.[3] It has an estimated combined mass of 168,000[5]solar masses (M\u2609) and is around 9.5\u00a0billion years old. The core region has a density of stars that is radiating 2.26 times solar luminosity (L\u2609) per cubic parsec.[6] There are 43 identified variable stars in the cluster.[3]  Map showing location of M72See also[edit]References and footnotes[edit]^ Shapley, Harlow; Sawyer, Helen B. (August 1927), “A Classification of Globular Clusters”, Harvard College Observatory Bulletin, 849 (849): 11\u201314, Bibcode:1927BHarO.849…11S.^ a b Goldsbury, Ryan;  et\u00a0al. (December 2010), “The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters”, The Astronomical Journal, 140 (6): 1830\u20131837, arXiv:1008.2755, Bibcode:2010AJ….140.1830G, doi:10.1088\/0004-6256\/140\/6\/1830, S2CID\u00a0119183070.^ a b c d Figuera Jaimes, R.;  et\u00a0al. (October 2011),  Henney, W. J.; Torres-Peimbert, S. (eds.), “XIII Latin American Regional IAU Meeting: (item) The Globular Cluster NGC 6981: Variable stars population, physical parameters and astrometry”, Revista Mexicana de Astronom\u00eda y Astrof\u00edsica, Serie de Conferencias, vol.\u00a040, pp.\u00a0235\u2013236, Bibcode:2011RMxAC..40..235F.^ “Messier 72”. SEDS Messier Catalog. Retrieved 30 April 2022.^ a b Boyles, J.;  et\u00a0al. (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\u00a0118649860.^ a b Sollima, A.;  et\u00a0al. (April 2008), “The correlation between blue straggler and binary fractions in the core of Galactic globular clusters”, Astronomy and Astrophysics, 481 (3): 701\u2013704, arXiv:0801.4511, Bibcode:2008A&A…481..701S, doi:10.1051\/0004-6361:20079082, S2CID\u00a03088769^ “NGC 6981”. SIMBAD. Centre de donn\u00e9es astronomiques de Strasbourg. Retrieved 2006-11-16.^ Garfinkle, Robert A. (1997), Star-Hopping: Your Visa to Viewing the Universe, Cambridge University Press, p.\u00a0266, ISBN\u00a0978-0521598897^ Burnham, Robert (1978), Burnham’s Celestial Handbook: An Observer’s Guide to the Universe Beyond the Solar System, Dover Books on Astronomy Series, vol.\u00a01 (2nd\u00a0ed.), Courier Dover Publications, pp.\u00a0188\u2013189, ISBN\u00a0978-0486235677^ Luginbuhl, Christian B.; Skiff, Brian A. (1998), Observing Handbook and Catalogue of Deep-Sky Objects (2nd\u00a0ed.), Cambridge University Press, p.\u00a025, ISBN\u00a0978-0521625562External links[edit]Messier 72, SEDS Messier pagesMessier 72, Galactic Globular Clusters Database pageMessier 72, LRGB CCD image based on two hours total exposureM-72 InformationMessier 72 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen \u03b1, X-Ray, Astrophoto, Sky Map, Articles and images"},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki2\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki2\/messier-72-wikipedia\/#breadcrumbitem","name":"Messier 72 – Wikipedia"}}]}]