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HD 152408

HD 152408
Location of WR 79a (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 16h 54m 58.5049s[1]
Declination −41° 09′ 03.092″[1]
Apparent magnitude (V) 5.81-5.85[2]
Characteristics
Spectral type WN9ha[3]
U−B color index −0.8[4]
B−V color index 0.017[4]
Variable type WR[2]
Astrometry
Radial velocity (Rv)−138[5] km/s
Proper motion (μ) RA: 0.47[1] mas/yr
Dec.: −2.25[1] mas/yr
Parallax (π)1.44 ± 0.34 mas[1]
Distance2,020+980
−510[3] pc
Absolute magnitude (MV)−7.1[3]
Details
Mass24.4[6] M☉
Radius32[7] R☉
Luminosity (bolometric)603,000[8] L☉
Temperature35,000[8] K
Other designations
HD 152408, WR 79a, HR 6272, HIP 82775, SAO 227425, CD–40°10919, Trumpler 24 159[9]
Database references
SIMBADdata
HD 152408 in Trumpler 24 is the brightest star, above centre, between the Prawn Nebula on the left and NGC 6231 on the right

HD 152408, also known as WR 79a, is a Wolf-Rayet star located in the constellation Scorpius, close to the galactic plane. Its distance is around 2,020 parsecs (6,500 lightyears) away from the Earth.[8]

HD 152408 lies in the north of the open cluster NGC 6231, the center of the OB association Scorpius OB1; it is not clear whether it is a part of the association or not.[10] With an apparent magnitude of about 5.77,[11] it is the third brightest Wolf-Rayet star. The other Wolf-Rayet stars that can be seen with the naked eye (although it can only be seen with the naked eye under excellent viewing conditions) are γ2 Velorum (WR 11), θ Muscae (WR 48), WR 22, WR 24 and HD 151932 (WR 78).

HD 152408 is about 24 times as massive as the Sun. Like most extremely massive stars, it is losing mass via its stellar wind. The total rate of mass loss is 2.4×10−5 M☉/yr.[8] With an effective temperature of 35,000 K, its bolometric luminosity is more than 600,000 L☉.

References

  1. ^ a b c d e van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  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. Bibcode:2009yCat....102025S.
  3. ^ a b c Crowther, Paul A.; Rate, Gemma (2020). "Unlocking Galactic Wolf–Rayet stars with Gaia DR2 – I. Distances and absolute magnitudes". Monthly Notices of the Royal Astronomical Society. 493 (1): 1512–1529. arXiv:1912.10125. Bibcode:2020MNRAS.493.1512R. doi:10.1093/mnras/stz3614. S2CID 209444955.
  4. ^ a b 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.
  5. ^ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Washington, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
  6. ^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
  7. ^ Lamers, H. J. G. L. M.; Nugis, T. (November 2002). "An explanation for the curious mass loss history of massive stars: From OB stars, through Luminous Blue Variables to Wolf-Rayet stars". Astronomy & Astrophysics. 395 (1): L1–L4. arXiv:astro-ph/0210388. Bibcode:2002A&A...395L...1L. doi:10.1051/0004-6361:20021381. ISSN 0004-6361. S2CID 18826723.
  8. ^ a b c d Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel; Schmutz, Werner; Sokal, Kimberly R. (2012-05-01). "New X-Ray Detections of WNL Stars". The Astronomical Journal. 143 (5): 116. arXiv:1203.5098. Bibcode:2012AJ....143..116S. doi:10.1088/0004-6256/143/5/116. ISSN 0004-6256. S2CID 119281411.
  9. ^ "HD 152408". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 6 February 2021.
  10. ^ Seggewiss, W.; Moffat, A. F. (1979). "The intrinsically bright Wolf-Rayet stars of type WN 7. III - The probable single SCO OB 1 star HD 151932 with variable He I envelope". Astronomy and Astrophysics. 72 (3): 332–338. Bibcode:1979A&A....72..332S.
  11. ^ Heske, A.; Wendker, H. J. (1985). "Further photometry and spectroscopy in the young cluster region TR 24/Sco OB 1". Astronomy and Astrophysics. 151: 309–314. Bibcode:1985A&A...151..309H.
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