Theta Crateris

Theta Crateris
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Crater
Right ascension 11h 36m 40.91335s[1]
Declination −09° 48′ 08.0912″[1]
Apparent magnitude (V) 4.70[2]
Characteristics
Spectral type B9.5 Vn[3]
U−B color index −0.18[2]
B−V color index −0.08[2]
Astrometry
Radial velocity (Rv)+2.09±3.78[4] km/s
Proper motion (μ) RA: −59.38[1] mas/yr
Dec.: +2.55[1] mas/yr
Parallax (π)11.63 ± 0.23 mas[1]
Distance280 ± 6 ly
(86 ± 2 pc)
Absolute magnitude (MV)+0.63[5]
Details
Mass2.79[6] M☉
Radius3.1[7] R☉
Luminosity107[8] L☉
Surface gravity (log g)3.96±0.14[6] cgs
Temperature11,524±392[6] K
Rotational velocity (v sin i)212[3] km/s
Age117[6] Myr
Other designations
θ Crt, 21 Crateris, BD−08°3202, FK5 1299, HD 100889, HIP 56633, HR 4468, SAO 138296.[9]
Database references
SIMBADdata

Theta Crateris (θ Crateris) is a solitary[10] star in the southern constellation of Crater. It is a photometric-standard star[11] that is faintly visible to the naked eye with an apparent visual magnitude of 4.70.[2] With an annual parallax shift of 11.63 mas as seen from Earth, it is located around 280 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.07 because of interstellar dust.[5]

This is a B-type main sequence star with a stellar classification of B9.5 Vn,[3] where the 'n' suffix indicates "nebulous" absorption lines due to rapid rotation. It is spinning with a projected rotational velocity of 212 km/s,[3] giving the star an oblate shape with an equatorial bulge that is an estimated 7% larger than the polar radius.[12] The star has 2.79[6] times the mass of the Sun and around 3.1[7] times the Sun's radius. With an age of about 117 million years,[6] it is radiating 107[8] times the solar luminosity from its outer atmosphere at an effective temperature of 11,524 K.[6]

References

  1. ^ a b c d e 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 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
  3. ^ a b c d Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
  4. ^ Becker, Juliette C.; et al. (April 2015), "Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra", The Astrophysical Journal Supplement Series, 217 (2): 13, arXiv:1503.03874, Bibcode:2015ApJS..217...29B, doi:10.1088/0067-0049/217/2/29, S2CID 33968873, 29.
  5. ^ a b Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID 119108982.
  6. ^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  7. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (3rd ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  8. ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  9. ^ "tet Crt -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-02-26.
  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. ^ Stritzinger, Maximilian; et al. (August 2005), "An Atlas of Spectrophotometric Landolt Standard Stars", The Publications of the Astronomical Society of the Pacific, 117 (834): 810–822, arXiv:astro-ph/0504244, Bibcode:2005PASP..117..810S, doi:10.1086/431468, S2CID 14771506.
  12. ^ Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474.
  • Skuppin, R.; Grewing, M.; Bianchi, L.; de Boer, K. S. (May 1987), "Interstellar absorption lines in the spectra of Theta Crateris and 14 Canum Venaticorum", Astronomy and Astrophysics, 177 (1–2): 228–232, Bibcode:1987A&A...177..228S.