S Doradus

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S Doradus
Observation data
Epoch J2000      Equinox J2000
Constellation Dorado
Right ascension 05h 18m 14.35s[1]
Declination −69° 15′ 01.10″[1]
Apparent magnitude (V) 9.565[1] (8.6 to 11.5 (B))[2]
Characteristics
Spectral type LBV
U−B color index –0.98[3]
B−V color index +0.11[3]
Variable type S Doradus[2]
Astrometry
Radial velocity (Rv) +228[4] km/s
Proper motion (μ) RA: 0.7[1] mas/yr
Dec.: 4.9[1] mas/yr
Distance 169,000 ly
(51,800 pc)
Absolute magnitude (MV) –7.6 (min)[5]
Details
Mass 45[6] M
Radius 100–380[6] R
Luminosity 1.0 × 106[6] L
Temperature 9–20,000[6] K
Other designations
CD-69 295, HD 35343, CPD-69 356, IRAS 05182-6918, AAVSO 0518-69.
Database references
SIMBAD data

S Doradus is one of the brightest stars in the Large Magellanic Cloud (LMC),[7] a satellite of the Milky Way. A hypergiant, it is one of the most luminous stars known (sometimes more luminous than −10 absolute magnitude), but so far away that it is invisible to the naked eye.

S Doradus is the brightest member of the open cluster NGC 1910, visible in binoculars as a bright condensation within the main bar of the LMC.[8]

This star belongs to its own eponymous S Doradus class of variable stars (these classes are usually named after their prototypes); also designated as luminous blue variables or LBVs. S Doradus exhibits long slow changes in brightness, punctuated by occasional outbursts. The spectrum is variable, a typical and defining characteristic of LBVs. In its quiescent phase, it has a B type spectrum (with emission) and a temperature around 20,000K. In outburst the temperature decreases and has been observed with the spectrum of an F supergiant and a temperature below 8,000K.[7]

See also[edit]

References[edit]

  1. ^ a b c d e Høg, E.; et al. (March 2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics 355: L27–L30, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862, ISBN 0333750888 
  2. ^ a b 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: 02025. Bibcode:2009yCat....102025S. 
  3. ^ a b Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series 34: 1–49, Bibcode:1978A&AS...34....1N 
  4. ^ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick. Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E. 
  5. ^ van Genderen, A.M. (2001). "S Doradus variables in the Galaxy and the Magellanic Clouds". Astronomy & Astrophysics 366 (2): 508–531. Bibcode:2001A&A...366..508V. doi:10.1051/0004-6361:20000022. 
  6. ^ a b c d Lamers, H. J. G. L. M. (February 6–10, 1995). "Observations and Interpretation of Luminous Blue Variables". Proceedings of IAU Colloquium 155, Astrophysical applications of stellar pulsation. Astrophysical applications of stellar pulsation. Astronomical Society of the Pacific Conference Series 83 (Cape Town, South Africa: Astronomical Society of the Pacific). pp. 176–191. Bibcode:1995ASPC...83..176L. 
  7. ^ a b Massey, Philip (February 2000), "An Unprecedented Change in the Spectrum of S Doradus: As Cool as It Gets", The Publications of the Astronomical Society of the Pacific 112 (768): 144–147, Bibcode:2000PASP..112..144M, doi:10.1086/316515 
  8. ^ Neugent, Kathryn F.; Massey, Philip; Morrell, Nidia (2012). "THE DISCOVERY OF A RARE WO-TYPE WOLF–RAYET STAR IN THE LARGE MAGELLANIC CLOUD". The Astronomical Journal 144 (6): 162. Bibcode:2012AJ....144..162N. doi:10.1088/0004-6256/144/6/162. ISSN 0004-6256. 

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