Summary
Xi Coronae Borealis (ξ CrB) is a binary star[3] 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.
| Observation data Epoch J2000.0 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 | |
| Spectral type | K0 III[3] |
| U−B color index | +0.80[2] |
| B−V color index | +0.97[2] |
| Astrometry | |
| Radial velocity (Rv) | −29.20±0.16[4] km/s |
| Proper motion (μ) | RA: −97.43[1] mas/yr Dec.: +107.45[1] mas/yr |
| Parallax (π) | 17.78 ± 0.25 mas[1] |
| Distance | 183 ± 3 ly (56.2 ± 0.8 pc) |
| Absolute magnitude (MV) | +1.04[5] |
| Details[4] | |
| Mass | 2.36[5] 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[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
As of 2009, the pair had an angular separation of 91 mas along a position angle of 139.4°.[7] The brighter member, component Aa,[7] is an evolved K-type giant star with a stellar classification of K0 III.[3] It is a red clump star that is generating energy by helium fusion at its core.[8] 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.[4]
References edit
- ^ a b c d e f van Leeuwen, F. (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, S2CID 18759600.
- ^ a b c d 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.
- ^ a b c 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ a b c 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, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209, S2CID 121883397.
- ^ a b c 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, arXiv:0805.2434, Bibcode:2008PASJ...60..781T, doi:10.1093/pasj/60.4.781, S2CID 16258166.
- ^ "ksi CrB". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-05-03.
- ^ a b Hartkopf, William I.; Mason, Brian D. (2009), "Speckle Interferometry at Mount Wilson Observatory: Observations Obtained in 2006-2007 and 35 New Orbits" (PDF), The Astronomical Journal, 138 (3): 813, Bibcode:2009AJ....138..813H, doi:10.1088/0004-6256/138/3/813, archived from the original on September 25, 2017.
- ^ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.