Short description: Star in the constellation Aquarius
Omega2 Aquarii, Latinised from ω2 Aquarii, is the Bayer designation for a triple star[9] system in the equatorial constellation of Aquarius. It can be seen with the naked eye, having an apparent visual magnitude of 4.49.[2] The approximate distance to this star, 149 light-years (46 parsecs), is known from parallax measurements taken during the Hipparcos mission.[1]
The primary component of this system is a massive, B-type main-sequence star with a stellar classification of B9 V.[3] This star has nearly double the radius of the Sun[6] and is spinning rapidly with a projected rotational velocity of 148 km/s.[7] The outer atmosphere has an effective temperature of 10,504 K,[6] giving it the blue-white hue of a B-type star.[10]
There is a close orbiting stellar companion of unknown type, with a third component at an angular separation of 5.7 arcseconds. The latter is a K-type main-sequence star with a visual magnitude of 9.5.[9] This system is among the 100 strongest stellar X-ray sources within 163 light-years (50 parsecs) of the Sun. It is emitting an X-ray luminosity of 1.2 × 1030 erg s−1.[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 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.
- ↑ 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1988mcts.book.....H.
- ↑ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication (Washington: Carnegie Institution of Washington), Bibcode: 1953GCRV..C......0W.
- ↑ 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 6.3 6.4 Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", The Astronomical Journal 129 (3): 1642–1662, doi:10.1086/427855, Bibcode: 2005AJ....129.1642F.
- ↑ 7.0 7.1 Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode: 2007A&A...463..671R.
- ↑ "105 Aqr -- Star in double system", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+222661, retrieved 2008-05-16.
- ↑ 9.0 9.1 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ "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.
- ↑ Makarov, Valeri V. (October 2003), "The 100 Brightest X-Ray Stars within 50 Parsecs of the Sun", The Astronomical Journal 126 (4): 1996–2008, doi:10.1086/378164, Bibcode: 2003AJ....126.1996M.
External links
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