Astronomy:LSS 4067

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LSS 4067
Observation data
Equinox J2000.0]] (ICRS)
Constellation Scorpius
Right ascension  17h 19m 05.548s[1]
Declination −29° 43′ 41.1989″[1]
Apparent magnitude (V) 11.44[2]
Characteristics
Spectral type O4.5Ifpe[3]
U−B color index +0.37[2]
B−V color index +1.49[2]
V−R color index +1.28[2]
Astrometry
Radial velocity (Rv)−51.0[4] km/s
Proper motion (μ) RA: −2.5[5] mas/yr
Dec.: −6.6[5] mas/yr
Distance9,500–12,700 ly
(2,900–3,900[2] pc)
Absolute magnitude (MV)−6.335[6]
Details
Mass120[7] M
Radius18.65[citation needed] R
Luminosity802,000[6] L
Surface gravity (log g)3.61[6] cgs
Temperature40,000[6] K
Rotational velocity (v sin i)<107[4] km/s
Other designations
LS 4067, CD−38°11748, Hen 3-1374, HM 1 VB 4, TYC 7870-896-1, 2MASS J17190554-3848496
Database references
SIMBADdata

LSS 4067, also known as CD−38°11748, is an O-type blue supergiant star located in the constellation Scorpius, very close to the galactic plane. It is part of the open cluster HM 1,[8] although its distance is not well known; it may be anywhere between 9,500 and 12,700 light years (2900 to 3900 parsecs) away from the Earth. Despite being a blue supergiant, it is extremely reddened by interstellar extinction, so its apparent magnitude is brighter for longer-wavelength passbands.[2] Without the extinction, it is estimated that LS 4067 would be 5.8 magnitudes brighter, a naked eye star with an apparent magnitude of 5.3.[9]

Although the Gaia Data Release 2 parallax for LS 4067 is negative, a likely distance can be calculated from it. The star is thought to be between 8,202 and 14,084 pc away, statistically most likely at 10,170 pc.[10] It was catalogued as a member of the faint cluster Havlen-Moffat No. 1, but is no longer thought to be a member. The cluster lies about 3,300 pc.[2]

LSS 4067 has an absolute bolometric magnitude of −11.4,[7] making it one of the most luminous stars known. Indeed, many of the hottest and most luminous stars known are O-type supergiants, or Wolf-Rayet stars. LSS 4067 has an unusual spectrum, with various emission lines including N III and He II emission lines, thus the "f" in its spectral type.[4] Because of this unusual spectrum, classifying the star or deducing its properties has proved relatively difficult: for example, the effective temperature is predicted to be too cool and the surface gravity too high.[4]

See also

References

  1. 1.0 1.1 Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E. et al. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues 2246: II/246. Bibcode2003yCat.2246....0C. http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/246. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Vázquez, R. A.; Baume, G. (2001). "The open cluster Havlen-Moffat No. 1 revisited". Astronomy and Astrophysics 371 (3): 908–920. doi:10.1051/0004-6361:20010410. Bibcode2001A&A...371..908V. 
  3. Sota, A. (2014). "The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars". The Astrophysical Journal Supplement 211 (1): 10. doi:10.1088/0067-0049/211/1/10. Bibcode2014ApJS..211...10S. 
  4. 4.0 4.1 4.2 4.3 Williams, S. J. (2011). "Radial Velocities of Galactic O-type Stars. I. Short-term Constant Velocity Stars". The Astronomical Journal 142 (5): 146. doi:10.1088/0004-6256/142/5/146. Bibcode2011AJ....142..146W. 
  5. 5.0 5.1 Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode2000A&A...355L..27H. 
  6. 6.0 6.1 6.2 6.3 Nebot Gómez-Morán, A.; Oskinova, L. M. (2018). "The X-ray catalog of spectroscopically identified Galactic O stars. Investigating the dependence of X-ray luminosity on stellar and wind parameters". Astronomy and Astrophysics 620: A89. doi:10.1051/0004-6361/201833453. Bibcode2018A&A...620A..89N. 
  7. 7.0 7.1 Cite error: Invalid <ref> tag; no text was provided for refs named Massey
  8. "CD-38 11748". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=CD-38+11748. 
  9. Maíz Apellániz, J.; Barbá, R. H. (2018). "Optical-NIR dust extinction towards Galactic O stars". Astronomy and Astrophysics 613: A9. doi:10.1051/0004-6361/201732050. Bibcode2018A&A...613A...9M. 
  10. Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Mantelet, G.; Andrae, R. (2018). "Estimating Distance from Parallaxes. IV. Distances to 1.33 Billion Stars in Gaia Data Release 2". The Astronomical Journal 156 (2): 58. doi:10.3847/1538-3881/aacb21. Bibcode2018AJ....156...58B.