Jump to content

UY Scuti

Coordinates:Sky map18h27m36.53s,−12° 27′ 58.9″
Page semi-protected
From Wikipedia, the free encyclopedia
For the album, seeUY Scuti (album).

UY Scuti

DSS2image ofred supergiantstar UY Scuti (brightest star in the image), surrounded by a dense starfield
Observation data
EpochJ2000EquinoxJ2000
Constellation Scutum
Right ascension 18h27m36.5334s[1]
Declination −12° 27′ 58.866″[1]
Apparent magnitude(V) 8.29 - 10.56[2]
Characteristics
Evolutionary stage Redsupergiant[3]
Spectral type M2-M4Ia-Iab[2]
U−Bcolor index +3.29[4]
B−Vcolor index +3.00[5]
Variable type SRc[6]
Astrometry
Radial velocity(Rv)18.33±0.82[7]km/s
Proper motion(μ)RA:1.3[8]mas/yr
Dec.:−1.6[8]mas/yr
Parallax(π)0.5166 ± 0.0494mas[9]
Distance5,871+534
−446[10]ly
(1,800+164
−137[10]pc)
Absolute magnitude(MV)−6.2[11]
Details
Radius909[12]R☉
Luminosity124,000[12]L☉
Temperature3,550[12]K
Other designations
UY Sct,BD−12°5055,IRC−10422,RAFGL2162, HV 3805
Database references
SIMBADdata

UY Scuti(BD-12°5055) is ared supergiantstar,located 5,900light-yearsaway in the constellationScutum.It is also apulsating variable star,with a maximum brightness ofmagnitude8.29 and a minimum of magnitude 10.56, which is too dim fornaked-eyevisibility. It is considered to be one of thelargest known stars,with a radius estimated at 909solar radii(632 millionkilometres;4.23astronomical units), thus a volume of 750 million times that of the Sun. This estimate implies if it were placed at the center of theSolar System,itsphotospherewould extend past the orbit ofMarsor even theasteroid belt.

Nomenclature and history

Avisual bandlight curvefor UY Scuti, plotted fromASASdata[13]

UY Scuti was first catalogued in 1860 by German astronomers at theBonn Observatory,who were completing a survey of stars for theBonner Durchmusterung Stellar Catalogue.[14]It was designated BD-12°5055, the 5,055th star between 12°S and 13°S counting from 0hright ascension.

On detection in the second survey, the star was found to have changed slightly in brightness, suggesting that it was a newvariable star.In accordance with the international standard fordesignation of variable stars,it was called UY Scuti, denoting it as the 38th variable star of the constellation Scutum.[15]

UY Scuti is located a few degrees north of theA-typestarGamma Scutiand northeast of theEagle Nebula.Although the star is very luminous, it is, at its brightest, only 9th magnitude as viewed from Earth, due to its distance and location in theZone of Avoidancewithin theCygnus rift.[16]

Characteristics

The size of UY Scuti compared to Earth's orbit and the Sun (barely visible)

UY Scuti is a dust-enshrouded brightred supergiant[17]and is classified as asemiregular variablewith an approximate pulsation period of 740 days.[6][18][19]Based on an old radius of 1,708R☉,this pulsation would be anovertoneof the fundamental pulsation period, or it may be afundamental modecorresponding to a smaller radius.[20]

In the summer of 2012,AMBERinterferometrywith theVery Large Telescope(VLT) in theAtacama DesertinChilewas used to measure the parameters of three red supergiants near theGalactic Centerregion:[4]UY Scuti,AH Scorpii,andKW Sagittarii.They determined that all three stars are over 1,000 times bigger than theSunand over 100,000 times more luminous than the Sun. The stars' sizes were calculated using theRosseland radius,the location at which theoptical depthis2⁄3,[21]with distances adopted from earlier publications. UY Scuti was analyzed to be the largest and the most luminous of the three stars measured, at 1,708 ± 192R☉(1.188×109± 134,000,000km;7.94 ± 0.89AU) based on anangular diameterof5.48±0.10masand an assumed distance of2.9±0.317kiloparsecs(kpc) (about9,500±1,030 light-years) which was originally derived in 1970 based on the modelling of the spectrum of UY Scuti.[11]The luminosity is then calculated to be 340,000L☉at an effective temperature of3,365±134K,giving an initial mass of 25M☉(possibly up to 40M☉for a non-rotating star).[4]

A 2023 measurement based on the multimessenger monitoring ofsupernovae,puts the radius at a smaller value of 909R☉,together with a smaller luminosity of 124,000L☉and effective temperature of 3,550K.[12]Direct measurements of the parallax of UY Scuti published in theGaia Data Release 2give a parallax of0.6433±0.1059mas,[7]implying a closer distance of approximately 1.5 kiloparsecs (4,900 ly),[22]and consequently much lower luminosity and radius values of around 86,300–87,100L☉and 755R☉respectively.[23]However, theGaiaparallax might be unreliable, at least until further observations, due to a very high level of astrometric noise.[7]

The distance of UY Scuti has been re-measured by Bailer-Joneset al.in 2021, based on a method that uses the stellar parallax fromGaia EDR3,its color and apparent brightness, giving it a much closer distance of 1,800 pc (5,900 ly). [10]

UY Scuti has no known companion star and so its mass is uncertain. However, it is expected on theoretical grounds to be between 7 and 10M☉.[4]Mass is being lost at5.8×10−5M☉per year, leading to an extensive and complex circumstellar environment of gas and dust.[24]

Supernova

Based on current models ofstellar evolution,UY Scuti has begun to fuseheliumand continues to fuse hydrogen in a shell around the core. The location of UY Scuti deep within the Milky Way disc suggests that it is ametal-richstar.[25]

After fusing heavy elements, its core will begin to produce iron, disrupting the balance of gravity and radiation in its core and resulting in acore collapse supernova.It is expected that a star like UY Scuti should evolve back to hotter temperatures to become ayellow hypergiant,luminous blue variable,or aWolf–Rayet star,creating a strong stellar wind that will eject its outer layers and expose the core, before exploding as a typeIIb,IIn,or typeIb/Icsupernova.[26]

See also

References

  1. ^abHog, E.; Kuzmin, A.; Bastian, U.; Fabricius, C.; Kuimov, K.; Lindegren, L.; Makarov, V. V.; Roeser, S. (1998). "The TYCHO Reference Catalogue".Astronomy and Astrophysics.335:L65.Bibcode:1998A&A...335L..65H.
  2. ^ab"VSX: Detail for UY Sct".American Association of Variable Star Observers.Retrieved2018-09-20.
  3. ^Tabernero, H. M.; Dorda, R.; Negueruela, I.; Marfil, E. (2021). "The nature of VX Sagitarii".Astronomy & Astrophysics.646:A98.arXiv:2011.09184.doi:10.1051/0004-6361/202039236.S2CID227013580.
  4. ^abcdArroyo-Torres, B.; Wittkowski, M.; Marcaide, J. M.; Hauschildt, P. H. (2013). "The atmospheric structure and fundamental parameters of the red supergiants AH Scorpii, UY Scuti, and KW Sagittarii".Astronomy & Astrophysics.554:A76.arXiv:1305.6179.Bibcode:2013A&A...554A..76A.doi:10.1051/0004-6361/201220920.S2CID73575062.
  5. ^Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system".CDS/ADC Collection of Electronic Catalogues.2237:0.Bibcode:2002yCat.2237....0D.
  6. ^abKholopov, P. N.; Samus, N. N.; Kazarovets, E. V.; Perova, N. B. (1985). "The 67th Name-List of Variable Stars".Information Bulletin on Variable Stars.2681:1.Bibcode:1985IBVS.2681....1K.
  7. ^abcBrown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData Release 2: Summary of the contents and survey properties ".Astronomy & Astrophysics.616.A1.arXiv:1804.09365.Bibcode:2018A&A...616A...1G.doi:10.1051/0004-6361/201833051.Gaia DR2 record for this sourceatVizieR.
  8. ^abHøg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5million brightest stars ".Astronomy and Astrophysics.355:L27.Bibcode:2000A&A...355L..27H.doi:10.1888/0333750888/2862.ISBN978-0333750889.
  9. ^Brown, A. G. A.;et al. (Gaia collaboration) (2021)."GaiaEarly Data Release 3: Summary of the contents and survey properties ".Astronomy & Astrophysics.649:A1.arXiv:2012.01533.Bibcode:2021A&A...649A...1G.doi:10.1051/0004-6361/202039657.S2CID227254300.(Erratum:doi:10.1051/0004-6361/202039657e).Gaia EDR3 record for this sourceatVizieR.
  10. ^abcBailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Demleitner, M.; Andrae, R. (2021)."Estimating Distances from Parallaxes. V. Geometric and Photogeometric Distances to 1.47 Billion Stars in Gaia Early Data Release 3".The Astronomical Journal.161(3): 147.arXiv:2012.05220.Bibcode:2021AJ....161..147B.doi:10.3847/1538-3881/abd806.S2CID228063812.Data about this star can be seenhere.
  11. ^abLee, T. A. (1970)."Photometry of high-luminosity M-type stars".Astrophysical Journal.162:217.Bibcode:1970ApJ...162..217L.doi:10.1086/150648.
  12. ^abcdHealy, Sarah; Horiuchi, Shunsaku; Molla, Marta Colomer; Milisavljevic, Dan; Tseng, Jeff; Bergin, Faith; Weil, Kathryn; Tanaka, Masaomi (2024-03-23), "Red Supergiant Candidates for Multimessenger Monitoring of the Next Galactic Supernova",Monthly Notices of the Royal Astronomical Society,529(4): 3630–3650,arXiv:2307.08785,Bibcode:2024MNRAS.529.3630H,doi:10.1093/mnras/stae738,ISSN0035-8711
  13. ^"ASAS All Star Catalogue".The All Sky Automated Survey.Retrieved8 December2021.
  14. ^Bonner Durchmusterung (Argelander 1859–1862)(clicking on "bd.gz" downloads the gzipped 10.1MB catalogue)
  15. ^Prager, R. (1927). "Katalog und Ephemeriden veraenderlicher Sterne fuer 1927".Kleine Veroeffentlichungen der Universitaetssternwarte zu Berlin Babelsberg.1:1.i.Bibcode:1927KVeBB...1....1P.
  16. ^"UY Sct (UY Scuti)".kusastro.Retrieved15 January2016.
  17. ^Van Loon, J. Th.; Cioni, M.-R. L.; Zijlstra, A. A.; Loup, C. (2005). "An empirical formula for the mass-loss rates of dust-enshrouded red supergiants and oxygen-rich Asymptotic Giant Branch stars".Astronomy and Astrophysics.438(1): 273–289.arXiv:astro-ph/0504379.Bibcode:2005A&A...438..273V.doi:10.1051/0004-6361:20042555.S2CID16724272.
  18. ^Whiting, Wendy A. (1978). "Observations of Three Variable Stars in Scutum".The Journal of the American Association of Variable Star Observers.7(2): 71.Bibcode:1978JAVSO...7...71W.
  19. ^Jura, M.; Kleinmann, S. G. (1990)."Mass-losing M supergiants in the solar neighborhood".The Astrophysical Journal Supplement Series.73:769.Bibcode:1990ApJS...73..769J.doi:10.1086/191488.
  20. ^Joyce, Meridith; Leung, Shing-Chi; Molnár, László; Ireland, Michael; Kobayashi, Chiaki; Nomoto, Ken'Ichi (2020)."Standing on the Shoulders of Giants: New Mass and Distance Estimates for Betelgeuse through Combined Evolutionary, Asteroseismic, and Hydrodynamic Simulations with MESA".The Astrophysical Journal.902(1): 63.arXiv:2006.09837.Bibcode:2020ApJ...902...63J.doi:10.3847/1538-4357/abb8db.S2CID221507952.
  21. ^Wehrse, R.; Scholz, M.; Baschek, B. (June 1991). "The parameters R and Teff in stellar models and observations".Astronomy and Astrophysics.246(2): 374–382.Bibcode:1991A&A...246..374B.
  22. ^Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Mantelet, G.; Andrae, R. (2018)."Estimating Distance from Parallaxes. IV. Distances to 1.33Billion Stars in Gaia Data Release 2 ".The Astronomical Journal.156(2): 58.arXiv:1804.10121.Bibcode:2018AJ....156...58B.doi:10.3847/1538-3881/aacb21.S2CID119289017.
  23. ^Messineo, M.; Brown, A. G. A. (2019)."A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2".The Astronomical Journal.158(1): 20.arXiv:1905.03744.Bibcode:2019AJ....158...20M.doi:10.3847/1538-3881/ab1cbd.S2CID148571616.
  24. ^Sylvester, R. J.; Skinner, C. J.; Barlow, M. J. (1998)."Silicate and hydrocarbon emission from Galactic M supergiants"(PDF).Monthly Notices of the Royal Astronomical Society.301(4): 1083–1094.Bibcode:1998MNRAS.301.1083S.doi:10.1046/j.1365-8711.1998.02078.x.
  25. ^Meynet, Georges (2008). Israelian, Garik (ed.).The metal-rich universe.Cambridge:Cambridge University Press.ISBN9780521879989.Retrieved15 January2016.
  26. ^Groh, Jose H.; Meynet, Georges; Georgy, Cyril; Ekström, Sylvia (2013). "Fundamental properties of core-collapse supernova and GRB progenitors: Predicting the look of massive stars before death".Astronomy & Astrophysics.558:A131.arXiv:1308.4681.Bibcode:2013A&A...558A.131G.doi:10.1051/0004-6361/201321906.S2CID84177572.
Retrieved from "https://en.wikipedia.org/w/index.php?title=UY_Scuti&oldid=1239525530"