Astronomy:Theta Arae
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Short description: Star in the constellation Ara
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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[1] mas |
| Distance | 810 ± 30 ly (249 ± 9 pc) |
| Absolute magnitude (MV) | −3.33[5] |
| Details | |
| Mass | 8.9 ± 0.1[6] M☉ |
| Radius | 20.1[7] R☉ |
| Luminosity | 3,450[5] L☉ |
| Surface gravity (log g) | 2.70[8] cgs |
| Temperature | 17,231 ± 231[7] K |
| Rotational velocity (v sin i) | 95[9] km/s |
| Age | 28.2 ± 4.7[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Theta Arae, Latinized from 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[6] times the mass of the Sun and is over 20[7] times the Sun's radius. The outer atmosphere of this star has an effective temperature of 17,231 K;[7] 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.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement 15: 459, doi:10.1086/190168, Bibcode: 1968ApJS...15..459G.
- ↑ 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ Wielen, R. et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg (Astronomisches Rechen-Institut Heidelberg) 35 (35): 1, Bibcode: 1999VeARI..35....1W.
- ↑ 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 6.2 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, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T.
- ↑ 7.0 7.1 7.2 7.3 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 (3): 601–605, doi:10.1093/mnras/189.3.601, Bibcode: 1979MNRAS.189..601U.
- ↑ 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, doi:10.1111/j.1365-2966.2010.16392.x, Bibcode: 2010MNRAS.404.1306F.
- ↑ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago 239 (1): 1, Bibcode: 1970CoAsi.239....1B.
- ↑ "* tet Ara". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+tet+Ara.
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16
External links
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