One of the faintest constellations in the night sky, Mensa contains no apparently bright stars—the brightest, Alpha Mensae, is barely visible in suburban skies. Part of the Large Magellanic Cloud, several star clusters and a quasar lie in the area covered by the constellation, and at least three of its star systems have been found to have exoplanets.
History
Originally named "Montagne de la Table" or "Mons Mensae",[1] Mensa was created by Nicolas-Louis de Lacaille out of dim Southern Hemisphere stars in honor of Table Mountain, a South African mountain overlooking Cape Town, near the location of Lacaille's observatory. He recalled that the Magellanic Clouds were sometimes known as Cape clouds, and that Table Mountain was often covered in clouds when a southeasterly stormy wind blew. Hence he made a "table" in the sky under the clouds.[2] Lacaille had observed and catalogued 10,000 southern stars during a two-year stay at the Cape of Good Hope. He devised 14 new constellations in uncharted regions of the Southern Celestial Hemisphere not visible from Europe. Mensa was the only constellation that did not honor an instrument symbolic of the Age of Enlightenment.[3] Sir John Herschel proposed shrinking the name to one word in 1844, noting that Lacaille himself had abbreviated some of his constellations thus.[4]
Although the stars of Mensa do not feature in any ancient mythology, the mountain it is named after has a rich mythology. Called "Tafelberg" in Dutch and German, it has two neighboring mountains called "Devil's Peak" and "Lion's Head". Table Mountain features in the mythology of the Cape of Good Hope, notorious for its storms. Explorer Bartolomeu Dias saw the mountain as a mythical anvil for storms.
Characteristics
Mensa is bordered by Dorado to the north, Hydrus to the northwest and west, Octans to the south, Chamaeleon to the east and Volans to the northeast. Covering 153.5 square degrees and 0.372% of the night sky, it ranks 75th of the 88 constellations in size.[5] The three-letter abbreviation for the constellation, as adopted by the IAU in 1922, is "Men".[6] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of eight segments. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 03h 12m 55.9008s and 07h 36m 51.5289s, while the declination coordinates are between −69.75° and −85.26°.[7] The whole constellation is visible to observers south of latitude 5°N.[5][a]
Lacaille gave eleven stars in the constellation Bayer designations, using the Greek alphabet to label them Alpha through to Lambda Mensae (excluding Kappa). Gould later added Kappa, Mu, Nu, Xi and Pi Mensae. Stars as dim as these were not generally given designations; however, Gould felt their closeness to the South Celestial Pole warranted their naming.[2]Alpha Mensae is the brightest star with a barely visible apparent magnitude of 5.09,[8] making it the only constellation with no star above magnitude 5.0.[9] Overall, there are 22 stars within the constellation's borders brighter than or equal to apparent magnitude 6.5.[b][5]
Alpha Mensae is a solar-type star (class G7V) 33.32 ± 0.02 light-years from Earth.[11] It came to within 11 light-years from Earth around 250,000 years ago and would have been considerably brighter back then—nearly of second magnitude.[12] An infrared excess has been detected around this star, indicating the presence of a circumstellar disk at a radius of over 147 astronomical units (AU). The estimated temperature of this dust is below 22 K.[13] However, data from Herschel Space Observatory failed to confirm this excess, leaving the finding in doubt.[14] No planetary companions have yet been discovered around it. It has a red dwarf companion star at an angular separation of 3.05 arcseconds; equivalent to a projected separation of roughly 30 AU.[8][15][16]
Gamma Mensae is the second-brightest star in the constellation, at magnitude 5.19.[17] Located 104.9 ± 0.5 light-years from Earth,[11] it is an ageing (10.6 billion year-old) star around 1.04 times as massive as the Sun. It has swollen to around 5 times the solar radius,[18] becoming an orange giant of spectral type K2III.[19]
Beta Mensae is slightly fainter at magnitude 5.31.[17] Located 660 ± 10 light-years from Earth,[11] it is a yellow giant of spectral type G8III, around 3.6 times as massive and 513 times as luminous as the Sun. It is 270 million years old,[20] and lies in front of the Large Magellanic Cloud.[17]
Zeta and Eta Mensae have infrared excesses suggesting they too have circumstellar disks of dust.[21][22] Zeta Mensae is an ageing white giant of spectral type A5 III around 394 ± 4 light-years from Earth,[23][11] and Eta Mensae is an orange giant of spectral type K4 III,[22] lying 650 ± 10 light-years away from Earth.[11]
Pi Mensae is a solar-type (G1) star 59.62 ± 0.07 light-years distant.[11] In 2001, a substellar companion was discovered in an eccentricorbit.[24] Incorporating more accurate Hipparcos data yields a mass range for the companion to be anywhere from 10.27 to 29.9 times that of Jupiter. This confirms its substellar nature with the upper limit of mass putting it in the brown dwarf range.[25] The discovery of a second substellar companion—a super-Earth—was announced on 16 September 2018. It takes 6.27 days to complete its orbit and is the first exoplanet detected by the Transiting Exoplanet Survey Satellite (TESS) submitted for publication.[26]
HD 39194 is an orange dwarf of spectral type K0V and magnitude 8.08, located 86.21 ± 0.09 light-years distant.[11] Three planets in close orbit were discovered by the High Accuracy Radial Velocity Planet Searcher (HARPS) in 2011. The three take 5.6, 14 and 34 days to complete an orbit around their star, and have minimum masses 3.72, 5.94 and 5.14 times that of the Earth respectively.[29]
Variable stars
TZ Mensae is an eclipsing binary that varies between magnitude 6.2 and 6.9 every 8.57 days.[9] It is composed of two white main sequence stars in close orbit. One of these is of spectral type A0V, has a radius twice as that of the Sun and is 2.5 times as massive. The other, an A8V spectral type, has a radius 1.4 times that of the Sun and is 1.5 times as massive.[30][31]
UX Mensae is another eclipsing binary system composed of two young stars around 1.2 times as massive as the Sun and 2.2 ± 0.5 billion years of age,[32] orbiting each other every 4.19 days.[33] The system is 338.2 ± 0.9 light-years distant.[11]
TY Mensae is another eclipsing binary system classified as a W Ursae Majoris variable; the two components are so close that they share a common envelope of stellar material. The larger star has been calculated to be 1.86 times as massive, have 1.85 times the diameter and is 13.6 times as luminous, while the smaller is 0.4 times as massive, 0.84 times the diameter, and 1.7 times as luminous as the Sun. Their surface temperatures have been calculated at 8164 and 7183 K respectively.[34]
YY Mensae is an orange giant of spectral type K1III around 2.2 times as massive as the Sun, with 12.7 times its diameter and 70 times its luminosity. A rapidly rotating star with a period of 9.5 days, it is a strong emitter of X-rays and belongs to a class of star known as FK Comae Berenices variables.[35] These stars are thought to have formed with the merger of two stars in a contact binary system.[36] With an apparent magnitude of 8.05, it is 707 ± 6 light-years distant.[11]
AH Mensae is a cataclysmic variable star system composed of a white dwarf and a red dwarf that orbit each other every 2 hours 57 minutes. The stars are close enough that the white dwarf strips material off the red dwarf, creating an accretion disc that periodically ignites with a resulting brightening of the system.[37]
TU Mensae is another cataclysmic variable composed of a red dwarf and white dwarf. The orbital period of 2 hours 49 minutes is one of the longest for cataclysmic variable systems exhibiting brighter outbursts, known as superhumps. The normal outbursts result in an increase in brightness lasting around a day every 37 days, while the superhumps last 5–20 days and take place every 194 days.[38]
AO Mensae is a faint star of magnitude 9.8. An orange dwarf that has 80% the size and mass of the Sun,[39] it is also a BY Draconis variable.[40] These are a class of stars with starspots prominent enough that the star changes brightness as it rotates.[41] It is a member of the Beta Pictoris moving group, a loose association of young stars moving across the galaxy.[39]
Other stars
WISE 0535−7500 is a binary system composed of two sub-brown dwarfs of spectral class cooler than Y1 located 47 ± 3 light-years away. Unable to be separated by observations to date, they are presumed to be of similar mass—8 to 20 times that of Jupiter—and are less than one AU apart.[42]
Deep-sky objects
The Large Magellanic Cloud lies partially within Mensa's boundaries,[44] although most of it lies in neighbouring Dorado.[9] It is a satellite galaxy of the Milky Way, located at a distance of 163,000 light-years.[45] Among its stars within Mensa are W Mensae, an unusual yellow-white supergiant that belongs to a rare class of star known as a R Coronae Borealis variable,[46]HD 268835, a blue hypergiant that is girded by a vast circumstellar disk of dust,[47] and R71, a luminous blue variable star that brightened in 2012 to over a million times as luminous as the Sun.[48] Also within the galaxy is NGC 1987, a globular cluster estimated to be around 600 million years old that has a significant number of red ageing stars,[49] and NGC 1848, a 27 million year old open cluster.[50] Mensa contains several described open clusters, most of which can be only be clearly observed from large telescopes.[51]
PKS 0637-752 is a distant quasar with a calculated redshift of z = 0.651. It was chosen as the first target of the then newly-operational Chandra X-Ray Observatory in 1999. The resulting images revealed a gas jet approximately 330,000 light-years long. It is visible at radio, optical and x-raywavelengths.[52]
Notes
^While parts of the constellation technically rise above the horizon to observers between 5°N and 20°N, stars within a few degrees of the horizon are practically unobservable.[5]
^Objects of magnitude 6.5 are among the faintest visible to the unaided eye in suburban–rural transition night skies.[10]
^"HD 43834B – Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 26 March 2010. (details on the stellar properties of the companion star)
^Reffert, S.; Quirrenbach, A. (2011). "Mass constraints on substellar companion candidates from the re-reduced Hipparcos intermediate astrometric data: nine confirmed planets and two confirmed brown dwarfs". Astronomy & Astrophysics. 527. id.A140. arXiv:1101.2227. Bibcode:2011A&A...527A.140R. doi:10.1051/0004-6361/201015861. S2CID54986291.
^Huang, Chelsea Xu; Burt, Jennifer; Vanderburg, Andrew; Günther, Maximilian N.; Shporer, Avi; Dittmann, Jason A.; Winn, Joshua N.; Wittenmyer, Rob; Sha, Lizhou; Kane, Stephen R.; Ricker, George R.; Vanderspek, Roland; Latham, David W.; Seager, Sara; Jenkins, Jon; Caldwell, Douglas A.; Collins, Karen A.; Guerrero, Natalia; Smith, Jeffrey C.; Quinn, Sam; Udry, Stéphane; Pepe, Francesco; Bouchy, François; Sé gransan, Damien; Lovis, Christophe; Ehrenreich, David; Marmier, Maxime; Mayor, Michel; Wohler, Bill; Haworth, Kari; Morgan, Edward; Fausnaugh, Michael; Charbonneau, David; Narita, Norio (2018). "TESS Discovery of a Transiting Super-Earth in the Π Mensae System". The Astrophysical Journal Letters. 868 (2): L39. arXiv:1809.05967. Bibcode:2018ApJ...868L..39H. doi:10.3847/2041-8213/aaef91. PMC6662726. PMID31360431.
^Brandão, I.M.; Dogan, G.; Christensen-Dalsgaard, J.; Cunha, M.S.; Bedding, T.R.; Metcalfe, T.S.; Kjeldsen, H.; Bruntt, H.; Arentoft, T. (2011). "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets". Astronomy and Astrophysics. arXiv:1109.2497. Bibcode:2011arXiv1109.2497M.
^Andersen, J.; Clausen, J.V.; Magain, P. (1989). "Absolute dimensions of eclipsing binaries. XIV – UX Mensae". Astronomy and Astrophysics. 211 (2): 346–52. Bibcode:1989A&A...211..346A.
^Maceroni, C.; van't Veer, F. (1996). "The properties of W Ursae Majoris contact binaries: new results and old problems". Astronomy and Astrophysics. 311: 523–31. Bibcode:1996A&A...311..523M.
^Audard, Marc; Telleschi, Alessandra; Güdel, Manuel; Skinner, Stephen L.; Pallavicini, Roberto; Mitra-Kraev, Urmila (2004). "Some like it hot: the X-ray emission of the giant star YY Mensae". Astrophys. J. 617 (1): 531–50. arXiv:astro-ph/0408345. Bibcode:2004ApJ...617..531A. doi:10.1086/424590. S2CID5086347.
^Gänsicke, B.T.; Koester, D. (1999). "SW Ursae Majoris, CU Velorum and AH Mensae: three more accreting white dwarfs unveiled?". Astronomy and Astrophysics. 346: 151–57. Bibcode:1999A&A...346..151G.
^Sion, Edward M.; Gänsicke, Boris T.; Long, Knox S.; Szkody, Paula; Knigge, Christian; Hubeny, Ivan; deMartino, Domitilla; Godon, Patrick (2008). "Hubble Space Telescope STIS Spectroscopy of Long-Period Dwarf Novae in Quiescence". The Astrophysical Journal. 681 (1): 543–53. arXiv:0801.4703. Bibcode:2008ApJ...681..543S. doi:10.1086/586699. S2CID6346887.
^Samus, N.N.; Durlevich, O.V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
^Mehner, A.; Baade, D.; Groh, J.H.; Rivinius, T.; Hambsch, F.-J.; Bartlett, E.S.; Asmus, D.; Agliozzo, C.; Szeifert, T.; Stahl, O. (2017). "Spectroscopic and photometric oscillatory envelope variability during the S Doradus outburst of the luminous blue variable R71". Astronomy and Astrophysics. 608: A124. arXiv:1709.00160. Bibcode:2017A&A...608A.124M. doi:10.1051/0004-6361/201731829. S2CID54585370.
^Zinnecker, H.; Ferraro, F.; Fusi Pecci, F.; Renzini, Alvio; Buonanno, R.; Corsi, C.E.; Turndrup, D.M. (1991-02-28). "Infrared Imaging of Intermediate Age LMC/SMC Clusters". In Haynes, Raymond; Milne, Douglas (eds.). The Magellanic Clouds: Proceedings of the 148th Symposium of the International Astronomical Union, held in Sydney, Australia, July 9–13, 1990. New York: Springer Science & Business Media. pp. 228–30. ISBN978-0792311102.
Wagman, Morton (2003). Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others. Blacksburg, VA: The McDonald & Woodward Publishing Company. ISBN978-0939923786.
Способом самоубийства (суицида) называют любые действия, с помощью которых человек совершает самоубийство, намеренно уходя из жизни. Самоубийство не всегда завершается смертью, и неудавшаяся попытка самоубийства может привести к серьезным физическим травмам, долгосро...
Teater Nasional di Yangon Orkestra Simfoni Nasional Myanmar adalah sebuah orkestra nasional Burma (Myanmar). Dibentuk pada tahun 2001, orkestra milik negara yang berbasis di Yangon ini diizinkan untuk mengadakan konser musik klasik di hadapan publik hanya satu kali pada sepuluh tahun pertamanya. Setelah larangan konser dicabut pada Januari 2012, orkestra ini mengadakan pertunjukan publik keduanya pada bulan Juli 2012 dan melakukan debut internasional pada Kuil Angkor Wat di Kamboja, pada Dese...
Kapolda PapuaLambang Polda PapuaPetahanaInspektur Jenderal Polisi Mathius D. Fakhiri, S.I.K.sejak 18 Februari 2021KantorMapolda Papua, Koya Koso, Abepura, JayapuraDibentuk27 September 1959Pejabat pertamaAKBP. M. Sauni Kepolisian Daerah Papua dipimpin oleh seorang perwira tinggi Polri berpangkat Jenderal bintang dua atau Inspektur Jenderal Polisi dan saat ini di jabat oleh Inspektur Jenderal Polisi Mathius D. Fakhiri. Daftar Pejabat Berikut adalah para perwira tinggi Polri yang pernah men...
1972 Indian filmBadi PanthuluTheatrical release posterDirected byP. Chandrasekhara ReddyWritten byD. V. Narasa Raju (dialogues)Screenplay byP. Chandrasekhara ReddyStory bySirvaadkarProduced byP. PerrajuStarringN. T. Rama RaoAnjali DeviCinematographyK. S. PrasadEdited byV. Anki ReddyMusic byK. V. MahadevanProductioncompanyTriveni ProductionsRelease date 22 November 1972 (1972-11-22) Running time165 minutesCountryIndiaLanguageTelugu Badi Panthulu (transl. School Teacher) is...
1939 Polish Army unit Poznan ArmyActiveMar 23 - Sep 21, 1939Country PolandTypeHeadquartersSize4 divisions and 2 brigadesEngagementsBattle of the BzuraCommandersNotablecommandersTadeusz KutrzebaMilitary unit Poznan Army (March to September 1939)Parent unitPolish High CommandComponents14th Infantry Division17th Infantry Division25th Infantry Division26th Infantry DivisionWielkopolska Cavalry BrigadePodolska Cavalry Brigade A monument to Poznań army in Poznań. Army Poznań (Polish: Armia ...
German-style board game designer (born 1960) Henn 2017 in Essen, Germany. Dirk Henn (born 1960) is a German-style board game designer who was born in Bendorf, Germany. Dirk Henn is best known for his game Alhambra, which won the Spiel des Jahres and placed 2nd in the Deutscher Spiele Preis in 2003. Game Company Affiliation db-Spiele, Self-Publishing Company Queen Games Selected list of games a full list is available in the external links section. Carat, 1993 Rosenkönig, 1997 Wallenstein, 200...
American independent film made in 2005 In Memory of My FatherDirected byChris JaymesWritten byChris JaymesProduced byChris JaymesStarring Judy Greer Jeremy Sisto Chris Jaymes Christine Lakin Nicholle Tom Matt Keeslar Monet Mazur Pat Healy Ian Michael Cole CinematographyAbe LevyEdited byEric Michael ColeChris JaymesMusic byDaniel TeperProductioncompanyInterspot FilmDistributed bySundance ChannelRelease dates June 10, 2005 (2005-06-10) (CineVegas) June 2, 2006 ...
Painting by Giovanni Bellini Madonna and Child with Saint Peter and Saint SebastianArtistGiovanni BelliniYear1487MediumOil on panelDimensions84 cm × 61 cm (33 in × 24 in)LocationLouvre, Paris Madonna and Child with Saint Peter and Saint Sebastian is an 84 cm by 61 cm oil painting by Giovanni Bellini, dating to 1487 and bought in 1859 by the Louvre in Paris, where it still hangs today.[1] References ^ Catalogue entry vteGiovanni Bel...
قرية غول المض - قرية - تقسيم إداري البلد اليمن المحافظة محافظة حجة المديرية مديرية بكيل المير العزلة عزلة صبران السكان التعداد السكاني 2004 السكان 21 • الذكور 11 • الإناث 10 • عدد الأسر 5 • عدد المساكن 5 معلومات أخرى التوقيت توقيت اليمن (+3 غرينيتش) ت...
Class of 50 Austro-Hungarian (later Italian) 2-2-2 (later 2-4-0) locomotives This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (April 2018) (Learn how and when to remove this template message) LVCI 1–50, 155–164LOMB 1–35, VEN 1–25SFAI 31–90RA 31-52, RM 501–518FS Class 102FS Class 102 locomotive at the Esposizione di Torino in 1911Type and originPower...
Bagian dari seri tentangAgama Buddha Sejarah dan PenyebaranGaris waktu • Sidang agung • Asia Tenggara • Asia Timur • Tibet • Asia Tengah • Indonesia • Dunia Barat AliranTheravāda • Mahāyāna • Vajrāyāna • Sthaviravāda • Mahāsāṃghika Konsep UtamaTiga Permata • Ketuhanan • Lima Hukum Alam • Puasa • Saṃsāra • Tiga Corak Umum • Lima Agregat • Hukum Sebab Musaba...
American politician Jennifer McCormickMcCormick in 201844th Indiana Superintendent of Public InstructionIn officeJanuary 9, 2017 – January 11, 2021GovernorEric HolcombPreceded byGlenda RitzSucceeded byOffice abolished Personal detailsPolitical partyDemocratic (since 2021)Other politicalaffiliationsRepublican (until 2021)SpouseTrentChildren1EducationPurdue University (BA)Ball State University (MA)Indiana State University (PhD) Jennifer McCormick is an American politician and educato...
1987 studio album by the Dream Academy Not to be confused with Remembrance Day. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: Remembrance Days – news · newspapers · books · scholar · JSTOR (September 2023) (Learn how and when to remove this template message) Remembrance DaysStudio album by The Dream Ac...
American businessman This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article's tone or style may not reflect the encyclopedic tone used on Wikipedia. See Wikipedia's guide to writing better articles for suggestions. (December 2018) (Learn how and when to remove this template message) This biographical article is written like a résumé. Please help improve it by revising it to be neu...
River in Devon, England View of the River Plym at Laira looking north The River Plym is a river in Devon, England. It runs from Dartmoor in the centre of the county southwest to meet the River Meavy, then south towards Plymouth Sound. The river is popular with canoeists, and the Plym Valley Railway runs alongside a section of the river. Course The river's source is around 450 metres (1,480 ft) above sea level on Dartmoor, in an upland marshy area called Plym Head.[1][2] F...
Artikel ini sebatang kara, artinya tidak ada artikel lain yang memiliki pranala balik ke halaman ini.Bantulah menambah pranala ke artikel ini dari artikel yang berhubungan atau coba peralatan pencari pranala.Tag ini diberikan pada Oktober 2022. Keruntuhan progresif adalah sebuah proses ketika bagian bangunan utama mengalami kerusakan sehingga merusak bagian penghubung bangunan dan menyebabkan kerusakan bangunan lebih lanjut. [1] Penyebab dari keruntuhan progresif mungkin tidak disenga...
Energía sostenible Visión general Energía sostenible Combustible neutro en carbono Abandono de los combustibles fósiles Conservación energética Cogeneración Eficiencia energética Almacenamiento de energía Edificio verde Bomba de calor Energía baja en carbono Microgeneración Casa pasiva Energía renovable Biocombustible Geotérmica Hidroelectricidad Solar Marea Ola Viento Transporte sostenible Vehículo eléctrico Vehículo verde Complemento híbrido La conservación energética es ...
2017 film The IntruderFilm posterItalianL'intrusa Directed byLeonardo Di CostanzoWritten byLeonardo Di CostanzoMaurizio BraucciBruno OlivieroProduced byCarlo Cresto-DinaThierry LounasTiziana SoudaniStarringMarcello FonteRaffaella GiordanoCinematographyHélène LouvartEdited byCarlotta CristianiMusic byMarco CappelliAdam RudolphRelease date 22 May 2017 (2017-05-22) (Cannes) CountryItalyLanguageItalian The Intruder (Italian: L'Intrusa) is a 2017 Italian drama film directed by...
Typeface MetroCategorySans-SerifClassificationHumanist / GeometricDesigner(s)W.A. DwigginsFoundryLinotypeDate released1929 (Metrolite/black)1931 (Metrothin/medium)1932 (Metro No. 2)VariationsChronicle MetroMetro OfficeMetro Nova (shown)Also known asGeometric 415 Metro is a sans-serif typeface family created by William Addison Dwiggins and released by the American Mergenthaler Linotype Company from 1929 onwards.[1][2][3] Metro was Dwiggins's first typeface, which he cre...
عزلة غرب مستباء - عزلة - تقسيم إداري البلد اليمن[1] المحافظة محافظة حجة المديرية مديرية مستباء خصائص جغرافية إحداثيات 16°14′29″N 43°14′16″E / 16.24141°N 43.23779°E / 16.24141; 43.23779 الارتفاع 216 متر السكان التعداد السكاني 2004 السكان 20٬309 • الذكور 10٬676 ...