Summary
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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 |
| Distance | 9,500–12,700 ly (2,900–3,900[2] pc) |
| Absolute magnitude (MV) | −6.335[6] |
| Details | |
| Mass | 120[7] M☉ |
| Radius | 18.65[citation needed] R☉ |
| Luminosity | 802,000[6] L☉ |
| Surface gravity (log g) | 3.61[6] cgs |
| Temperature | 40,000[6] K |
| Rotational velocity (v sin i) | <107[4] km/s |
| Age | 1.10[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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 edit
References edit
- ^ a b Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
- ^ a b c d e f g Vázquez, R. A.; Baume, G. (2001). "The open cluster Havlen-Moffat No. 1 revisited". Astronomy and Astrophysics. 371 (3): 908–920. Bibcode:2001A&A...371..908V. doi:10.1051/0004-6361:20010410.
- ^ Sota, A.; et al. (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.
- ^ a b c d Williams, S. J.; et al. (2011). "Radial Velocities of Galactic O-type Stars. I. Short-term Constant Velocity Stars". The Astronomical Journal. 142 (5): 146. Bibcode:2011AJ....142..146W. doi:10.1088/0004-6256/142/5/146.
- ^ a b Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- ^ a b c d 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. arXiv:1808.07880. Bibcode:2018A&A...620A..89N. doi:10.1051/0004-6361/201833453. S2CID 73607059.
- ^ a b c Massey, P.; Degioia-Eastwood, K.; Waterhouse, E. (2001). "The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turnoffs. II. Results from 12 Galactic Clusters and OB Associations". The Astronomical Journal. 121 (2): 1050–1070. arXiv:astro-ph/0010654. Bibcode:2001AJ....121.1050M. doi:10.1086/318769. S2CID 53345173.
- ^ "CD-38 11748". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 19 January 2016.
- ^ Maíz Apellániz, J.; Barbá, R. H. (2018). "Optical-NIR dust extinction towards Galactic O stars". Astronomy and Astrophysics. 613: A9. arXiv:1712.09228. Bibcode:2018A&A...613A...9M. doi:10.1051/0004-6361/201732050. S2CID 119342685.
- ^ 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. arXiv:1804.10121. Bibcode:2018AJ....156...58B. doi:10.3847/1538-3881/aacb21. S2CID 119289017.