Theta Muscae

Theta Muscae
Location of θ Mus (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Musca
Right ascension 13h 08m 07.15286s[1]
Declination −65° 18′ 21.6819″[1]
Apparent magnitude (V) 5.53[2] (5.662 + 7.555[3])
Characteristics
θ Mus A
Spectral type WC5/6 + O6/7V + O9.5/B0Iab[4]
U−B color index −0.91[5]
B−V color index −0.43[3]
Variable type Eclipsing + WR[6]
B
Spectral type O9III[7]
U−B color index −0.90[5]
B−V color index −0.055[3]
Astrometry
Radial velocity (Rv)−28.4[8] km/s
Proper motion (μ) RA: −2.10[1] mas/yr
Dec.: −11.52[1] mas/yr
Parallax (π)0.26 ± 0.48 mas[1]
Distance7,400[4] ly
(2,270[4] pc)
Absolute magnitude (MV)−6.2[9]
Orbit[10]
Period (P)19.1375 d
Eccentricity (e)0.00 (assumed)
Inclination (i)49±6°
Semi-amplitude (K1)
(primary)		221±6 km/s
Details
WR
Mass<11.5[11] M☉
Luminosity234,000[11] L☉
O
Mass44[10] M☉
Luminosity295,000[12] L☉
Other designations
Theta Muscae, CD−64°699, HR 4952, HD 113904, HIP 64094, GSC 08997-02337, SAO 252162, PPM 359890, GC 17788, UCAC3 50-186265, IRAS 15465+2818, WR 48
Database references
SIMBADdata

Theta Muscae (θ Muscae) is a multiple star system in the southern constellation Musca ("the Fly"), containing a Wolf-Rayet star and two massive companions. With an apparent magnitude of 5.5, it is the second-brightest Wolf–Rayet star in the sky,[13] although much of the visual brightness comes from the massive companions and it is not one of the closest of its type.

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  2. ^ 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.
  3. ^ a b c Høg, 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 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862.
  4. ^ a b c Cite error: The named reference sugawara08 was invoked but never defined (see the help page).
  5. ^ a b Moffat, A. F. J.; Seggewiss, W. (1977). "The Wolf-Rayet binary theta Muscae". Astronomy and Astrophysics. 54: 607. Bibcode:1977A&A....54..607M.
  6. ^ 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.
  7. ^ Sota, A.; Maíz Apellániz, J.; Morrell, N. I.; Barbá, R. H.; Walborn, N. R.; Gamen, R. C.; Arias, J. I.; Alfaro, E. J. (2014). "The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars". The Astrophysical Journal Supplement. 211 (1): 10. arXiv:1312.6222. Bibcode:2014ApJS..211...10S. doi:10.1088/0067-0049/211/1/10. S2CID 118847528.
  8. ^ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Washington, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
  9. ^ Hidayat, Bambang; Admiranto, A. Gunawan; Van Der Hucht, Karel A. (1984). "Wolf-Rayet binaries: Evolutionary causes for their distribution in the Galaxy". Astrophysics and Space Science. 99 (1–2): 175–190. Bibcode:1984Ap&SS..99..175H. doi:10.1007/BF00650243. ISSN 0004-640X. S2CID 189850123.
  10. ^ a b Hill, G. M.; Moffat, A. F. J.; St-Louis, N. (1 October 2002). "Modelling the colliding-winds spectra of the 19-d WR + OB binary in the massive triple system Muscae". Monthly Notices of the Royal Astronomical Society. 335 (4): 1069–1078. Bibcode:2002MNRAS.335.1069H. doi:10.1046/j.1365-8711.2002.05694.x. ISSN 0035-8711. S2CID 121923927.
  11. ^ a b Nugis, T.; Lamers, H. J. G. L. M. (2000). "Mass-loss rates of Wolf-Rayet stars as a function of stellar parameters". Astronomy and Astrophysics. 360: 227. Bibcode:2000A&A...360..227N.
  12. ^ Sugawara, Y.; Tsuboi, Y.; Maeda, Y. (October 2008). "Redshifted emission lines and radiative recombination continuum from the Wolf-Rayet binary θ Muscae: evidence for a triplet system?". Astronomy & Astrophysics. 490 (1): 259–264. arXiv:0810.1208. Bibcode:2008A&A...490..259S. doi:10.1051/0004-6361:20079302. ISSN 0004-6361. S2CID 118447784.
  13. ^ C. de Loore; A.J. Willis (6 December 2012). Wolf-Rayet Stars: Observations, Physics, Evolution. Springer Science & Business Media. pp. 310–. ISBN 9789400979109.