HD 160529

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HD 160529
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 17h 41m 59.025s[1]
Declination −33° 30′ 13.71″[1]
Apparent magnitude (V) 6.66[2] (6.3 - 6.9[3])
Characteristics
Spectral type LBV
U−B color index +0.30[2]
B−V color index +1.21[2]
Variable type LBV
Astrometry
Radial velocity (Rv) -35[4] km/s
Proper motion (μ) RA: −1.75[1] mas/yr
Dec.: −1.49[1] mas/yr
Parallax (π) 0.54 ± 0.54[1] mas
Distance 2,500[5] pc
Absolute magnitude (MV) -8.9[6]
Details
Mass 13[6] M
Radius 150-330[3] R
Luminosity 290,000[5] L
Surface gravity (log g) 0.55[6] cgs
Temperature 8,000-12,000[3] K
Rotational velocity (v sin i) 45[3] km/s
Other designations
V905 Sco, HD 160529, CD -33°12361, SAO 209151, HIP 86624
Database references
SIMBAD data

HD 160529 (V905 Sco) is a Luminous Blue Variable (LBV) star located in the constellation of Scorpius. With an apparent magnitude of around +6.8 cannot be seen with the naked eye except under very favourable conditions, but it's easy to see with binoculars or amateur telescopes.

Physical characteristics[edit]

V905 Sco has a peculiar variable spectral type with emission lines and P Cygni profiles. At visual maximum it is similar to an A9 star and at minimum close to B8.[3] The distance has been estimated at 2.5 kiloparsecs (8,200 light years) based on the assumption of an absolute magnitude of -8.9.[6] However this distance is uncertain and values between 1.9 kiloparsecs and 3.5 kiloparsecs have been proposed.[3]

Working with a distance of 2.5 kiloparsecs, the radius varies from 150 R when quiescent to 330 R in outburst. The temperature also varies, from 8,000K in outburst to 12,000K when quiescent. With these parameters, the apparent visual magnitude varies by 0.5 and the bolometric luminosity is constant at 180,000 L.[3]

Estimates of the surface gravity lead to a mass of 13 M and a probable initial mass of 25 M This suggests that V905 Sco is a former red supergiant star.[6]

References[edit]

  1. ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. 
  2. ^ a b c 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 d e f g Stahl, O.; Gäng, T.; Sterken, C.; Kaufer, A.; Rivinius, T.; Szeifert, T.; Wolf, B. (March 2003). "Long-term spectroscopic monitoring of the Luminous Blue Variable HD 160529". Astronomy and Astrophysics 400: 279–291. arXiv:astro-ph/0212473. Bibcode:2003A&A...400..279S. doi:10.1051/0004-6361:20021908. 
  4. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. 
  5. ^ a b Nazé, Y.; Rauw, G.; Hutsemékers, D. (2012). "The first X-ray survey of Galactic luminous blue variables". Astronomy & Astrophysics 538: A47. arXiv:1111.6375. Bibcode:2012A&A...538A..47N. doi:10.1051/0004-6361/201118040. 
  6. ^ a b c d e Sterken, C.; Gosset, E.; Juttner, A.; Stahl, O.; Wolf, B.; Axer, M. (July 1991). "HD 160529 - a New Galactic Luminous Blue Variable". Astronomy and Astrophysics 247 (2): 383. Bibcode:1991A&A...247..383S.