Astronomy:Kappa Arae
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ara |
| Right ascension | 17h 26m 00.043s[1] |
| Declination | −50° 38′ 00.62″[1] |
| Apparent magnitude (V) | 5.200±0.009[2] |
| Characteristics | |
| Evolutionary stage | Giant[3] |
| Spectral type | G8 III[4] |
| B−V color index | +1.03±0.01[2] |
| Astrometry | |
| Radial velocity (Rv) | +17.8±0.1[5] km/s |
| Proper motion (μ) | RA: +13.004[1] mas/yr Dec.: +7.554[1] mas/yr |
| Parallax (π) | 7.5862 ± 0.0741[1] mas |
| Distance | 430 ± 4 ly (132 ± 1 pc) |
| Absolute magnitude (MV) | −0.49±0.06[2] |
| Details[2] | |
| Mass | 3.23±0.24 M☉ |
| Radius | 18.22±0.60 R☉ |
| Luminosity | 166.1±8.9 L☉ |
| Surface gravity (log g) | 2.56±0.15 cgs |
| Temperature | 4,855±48 K |
| Metallicity [Fe/H] | −0.058±0.037 dex |
| Rotational velocity (v sin i) | 1.0[6] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Kappa Arae is a single[8] star in the southern constellation of Ara. Its name is a Bayer designation that is Latinized from κ Arae, and abbreviated Kappa Ara or κ Ara. With an apparent visual magnitude of 5.20,[2] this star is faintly visible to the naked eye. Based upon parallax measurements, it is approximately 430 light-years (130 parsecs) distant from Earth, give or take a 4 light-year margin of error.[1] It is receding from the Sun with a radial velocity of +17.8 km/s.[5]
This is a giant star with a stellar classification of G8 III,[4] having exhausted the hydrogen at its core and evolved away from the main sequence. With 3.2 times the mass of the Sun, its outer envelope has expanded to about 18 times the Sun's radius. It is radiating 166 times the luminosity of the Sun from its photosphere at an effective temperature of 4,855 K.[2] This is hot enough for it to shine with the golden-hued glow of a G-type star.[9] It is a source for coronal X-ray emission and has been reported as a mild barium star, although the latter is questionable.[10]
Kappa Arae has two 14th magnitude optical companions that are at an angular distance of 25 and 30 arcseconds.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Ottoni, G. et al. (January 2022), "CORALIE radial-velocity search for companions around evolved stars (CASCADES): I. Sample definition and first results: Three new planets orbiting giant stars", Astronomy & Astrophysics 657: A87, doi:10.1051/0004-6361/202040078, ISSN 0004-6361, Bibcode: 2022A&A...657A..87O.
- ↑ Stassun, Keivan G. et al. (September 2019), "The Revised TESS Input Catalog and Candidate Target List" (in en), The Astronomical Journal 158 (4): 138, doi:10.3847/1538-3881/ab3467, ISSN 1538-3881, Bibcode: 2019AJ....158..138S.
- ↑ 4.0 4.1 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.
- ↑ 5.0 5.1 Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ Glebocki, R.; Gnacinski, P. (2005), "Catalog of Stellar Rotational Velocities", VizieR On-line Data Catalog: III/244. Originally Published in: 2005csss...13..571G; 2005yCat.3244....0G 3244, Bibcode: 2005yCat.3244....0G.
- ↑ "kap Ara". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=kap+Ara.
- ↑ 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.
- ↑ Jorissen, A. et al. (February 1996), "New X-ray sources detected among mild barium and S stars", Astronomy and Astrophysics 306: 467, Bibcode: 1996A&A...306..467J.
- ↑ Mason, Brian D. et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
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