Jump to content

Theta Arae

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Rjwilmsi (talk | contribs) at 08:15, 3 October 2014 (→‎References: Journal cites:, added 1 DOI using AWB (10473)). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Theta Arae
Diagram showing star positions and boundaries of the Ara constellation and its surroundings
The location of θ Arae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ara
Right ascension 18h 06m 37.87129s[1]
Declination –50° 05′ 29.3125″[1]
Apparent magnitude (V) +3.67[2]
Characteristics
Spectral type B2 Ib[3]
U−B color index –0.870[2]
B−V color index –0.109[2]
Astrometry
Radial velocity (Rv)+3.4[4] km/s
Proper motion (μ) RA: –8.27[1] mas/yr
Dec.: –8.70[1] mas/yr
Parallax (π)4.01 ± 0.15 mas[1]
Distance810 ± 30 ly
(249 ± 9 pc)
Details
Mass8.9 ± 0.1[5] M
Radius20.1[6] R
Surface gravity (log g)2.70[7] cgs
Temperature17,231 ± 231[6] K
Rotational velocity (v sin i)95[8] km/s
Age28.2 ± 4.7[5] Myr
Other designations
CD −50° 11720, FK5 1471, HD 165024, HIP 88714, HR 6743, SAO 245242.[9]

Theta Arae (θ Ara, θ Arae) is the Bayer designation for a star in the constellation Ara. It has an apparent visual magnitude of +3.67,[2] which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 4.01 mas,[1] Theta Arae is 810 light-years (250 parsecs) distant from the Earth.

This is a supergiant star with a stellar classification of B2 Ib.[3] It has nearly nine[5] times the mass of the Sun and is over 20[6] times the Sun's radius. The outer atmosphere of this star has an effective temperature of 17,231 K;[6] much hotter than the surface of the Sun. At this heat, the star shines with the characteristic blue-white hue of a B-type star.[10]

References

  1. ^ a b c d e f van Leeuwen, F. (November 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.
  2. ^ a b c d Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168.
  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. ^ Wielen, R.; et al. (1999), Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions, Astronomisches Rechen-Institut Heidelberg, Bibcode:1999VeARI..35....1W.
  5. ^ a b c Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (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.
  6. ^ a b c d Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189: 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601.
  7. ^ Fraser, M.; et al. (May 2010), "Atmospheric parameters and rotational velocities for a sample of Galactic B-type supergiants", Monthly Notices of the Royal Astronomical Society, 404 (3): 1306–1320, arXiv:1001.3337, Bibcode:2010MNRAS.404.1306F, doi:10.1111/j.1365-2966.2010.16392.x.
  8. ^ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1), Bibcode:1970CoAsi.239....1B.
  9. ^ "tet Ara -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2010-07-30.
  10. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-01-16

External links