G Centauri

(Redirected from HD 108257)

G Centauri is a single[10] star in the southern constellation of Centaurus. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of +4.82. This object is located approximately 450 light years from the Sun, based on parallax.[1] It is a member of the Lower Centaurus–Crux group of the Scorpius–Centaurus association, with the former having an age of about 17 million years.[11]

G Centauri
Observation data
Epoch J2000      Equinox J2000
Constellation Centaurus
Right ascension 12h 26m 31.75955s[1]
Declination −51° 27′ 02.2899″[1]
Apparent magnitude (V) 4.82[2]
Characteristics
Spectral type B3V(n)[3]
B−V color index −0.141±0.002[2]
Astrometry
Radial velocity (Rv)+5.0±4.2[2] km/s
Proper motion (μ) RA: −30.66[1] mas/yr
Dec.: −10.13[1] mas/yr
Parallax (π)7.28 ± 0.24 mas[1]
Distance450 ± 10 ly
(137 ± 5 pc)
Absolute magnitude (MV)−0.87[2]
Details
Mass6.2±0.1[4] M
Radius3.42[5] R
Luminosity483.06[2] L
Temperature13,732[6] K
Metallicity [Fe/H]−0.38±0.06[7] dex
Rotational velocity (v sin i)298±12[8] km/s
Age15.8±0.2[4] Myr
Other designations
G Cen, CD−50°6975, GC 16954, HD 108257, HIP 60710, HR 4732, SAO 239948, CCDM J12265-5127[9]
Database references
SIMBADdata

This object is a B-type main-sequence star with a stellar classification of B3V(n),[3] where the 'n' indicates "nebulous" (broad) lines due to rapid rotation. It is around 16[4] million years old with a projected rotational velocity of up to 298 km/s.[8] The star has six[4] times the mass of the Sun and 3.4[5] times the Sun's radius. It is radiating 483[2] times the luminosity of the Sun from its photosphere at an effective temperature of 13,732 K.[6] An infrared excess indicates a circumstellar disk of dust with a mean temperature of 50 K is orbiting the star at a separation of 717.8 AU.[5]

References

edit
  1. ^ a b c d e f van Leeuwen, F. (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 c d e f Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  4. ^ a b c d Tetzlaff, N.; et al. (January 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.
  5. ^ a b c Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series, 225 (1): 24, arXiv:1606.01134, Bibcode:2016ApJS..225...15C, doi:10.3847/0067-0049/225/1/15, S2CID 118438871, 15.
  6. ^ a b McDonald, I.; et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–357, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  7. ^ Gáspár, András; et al. (2016), "The Correlation between Metallicity and Debris Disk Mass", The Astrophysical Journal, 826 (2): 171, arXiv:1604.07403, Bibcode:2016ApJ...826..171G, doi:10.3847/0004-637X/826/2/171, S2CID 119241004.
  8. ^ a b Brown, A. G. A.; Verschueren, W. (1997), "High S/N Echelle spectroscopy in young stellar groups. II. Rotational velocities of early-type stars in SCO OB2", Astronomy and Astrophysics, 319: 811, arXiv:astro-ph/9608089, Bibcode:1997A&A...319..811B. Note: "The He i λ4026 line in this star is broader than the models. The value of vsini may thus be overestimated."
  9. ^ "G Cen". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-15.
  10. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  11. ^ Jang-Condell, Hannah; et al. (August 2015), "Spitzer IRS Spectra of Debris Disks in the Scorpius–Centaurus OB Association", The Astrophysical Journal, 808 (2): 19, arXiv:1506.05428, Bibcode:2015ApJ...808..167J, doi:10.1088/0004-637X/808/2/167, S2CID 118549483, 167.