Astronomy:Xi Coronae Borealis
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Corona Borealis |
| Right ascension | 16h 22m 05.82391s[1] |
| Declination | +30° 53′ 31.1837″[1] |
| Apparent magnitude (V) | 4.85[2] |
| Characteristics | |
| Evolutionary stage | red clump[3] |
| Spectral type | G9 IIIFe−0.5[4] |
| U−B color index | +0.80[2] |
| B−V color index | +0.97[2] |
| Astrometry | |
| Radial velocity (Rv) | −29.20±0.16[5] km/s |
| Proper motion (μ) | RA: −97.43[1] mas/yr Dec.: +107.45[1] mas/yr |
| Parallax (π) | 17.78 ± 0.25[1] mas |
| Distance | 183 ± 3 ly (56.2 ± 0.8 pc) |
| Absolute magnitude (MV) | +1.04[6] |
| Details[5] | |
| Mass | 2.36[6] M☉ |
| Radius | 8 R☉ |
| Luminosity | 36 L☉ |
| Surface gravity (log g) | 2.9 cgs |
| Temperature | 4,853±5 K |
| Metallicity [Fe/H] | −0.08 dex |
| Rotational velocity (v sin i) | 2.8 km/s |
| Age | 676[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Xi Coronae Borealis (ξ CrB) is a binary star[8] system in the northern constellation of Corona Borealis. It is visible to the naked eye with a combined apparent visual magnitude of 4.85.[2] Based upon an annual parallax shift of 17.78 mas as seen from the Earth,[1] it is located about 183 light years from the Sun.
As of 2009, the pair had an angular separation of 91 mas along a position angle of 139.4°.[9] The brighter member, component Aa,[9] is an evolved G-type giant star with a stellar classification of G9 III. It is a red clump star that is generating energy by helium fusion at its core.[3] The star has an estimated 2.36 times the mass of the Sun and has expanded to 8 times the Sun's radius. It is radiating 36 times the solar luminosity from its photosphere at an effective temperature of 4,853 K.[5]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (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 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
- ↑ 3.0 3.1 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode: 2000ApJ...539..732A.
- ↑ Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins Catalog of Revised MK Types for the Cooler Stars", The Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K.
- ↑ 5.0 5.1 5.2 Massarotti, Alessandro et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal 135 (1): 209–231, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ 6.0 6.1 6.2 Takeda, Yoichi et al. (August 2008), "Stellar Parameters and Elemental Abundances of Late-G Giants", Publications of the Astronomical Society of Japan 60 (4): 781–802, doi:10.1093/pasj/60.4.781, Bibcode: 2008PASJ...60..781T.
- ↑ "ksi CrB". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ksi+CrB.
- ↑ 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.
- ↑ 9.0 9.1 Hartkopf, William I.; Mason, Brian D. (2009), "Speckle Interferometry at Mount Wilson Observatory: Observations Obtained in 2006-2007 and 35 New Orbits", The Astronomical Journal 138 (3): 813, doi:10.1088/0004-6256/138/3/813, Bibcode: 2009AJ....138..813H, https://apps.dtic.mil/sti/pdfs/ADA505053.pdf.
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