Astronomy:20 Boötis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 19m 45.23505s[1] |
| Declination | +16° 18′ 24.9955″[1] |
| Apparent magnitude (V) | 4.84[2] |
| Characteristics | |
| Spectral type | K3 III[3] |
| B−V color index | 1.228±0.001[2] |
| Astrometry | |
| Radial velocity (Rv) | −8.25±0.43[2] km/s |
| Proper motion (μ) | RA: –141.521[1] mas/yr Dec.: +60.274[1] mas/yr |
| Parallax (π) | 17.8379 ± 0.1894[1] mas |
| Distance | 183 ± 2 ly (56.1 ± 0.6 pc) |
| Absolute magnitude (MV) | 1.01±0.09[4] |
| Details[4] | |
| Mass | 1.14±0.19 M☉ |
| Radius | 12.18+0.26 −0.36[1] R☉ |
| Luminosity | 51.99±0.66[1] L☉ |
| Surface gravity (log g) | 2.36±0.08 cgs |
| Temperature | 4,472 K |
| Metallicity [Fe/H] | 0.16 dex |
| Rotation | 848 days[5] |
| Rotational velocity (v sin i) | 1.0[5] km/s |
| Age | 5.21±2.28 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
20 Boötis is a single[7] star in the northern constellation of Boötes, located 183 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.84.[2] The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.154 arc seconds per annum.[8] It is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.[2]
This is an aging K-type giant star with a stellar classification of K3 III.[3] It is a red clump giant,[9] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The star is around five billion years old with 1.1[4] times the mass of the Sun and has expanded to 12[1] times the Sun's radius. It is radiating 52[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,472 K.[4]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Roman, Nancy G. (July 1952), "The Spectra of the Bright Stars of Types F5-K5", Astrophysical Journal 116: 122, doi:10.1086/145598, Bibcode: 1952ApJ...116..122R.
- ↑ 4.0 4.1 4.2 4.3 da Silva, L. et al. (November 2006), "Basic physical parameters of a selected sample of evolved stars", Astronomy and Astrophysics 458 (2): 609–623, doi:10.1051/0004-6361:20065105, Bibcode: 2006A&A...458..609D.
- ↑ 5.0 5.1 Setiawan, J. et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics 421: 241–254, doi:10.1051/0004-6361:20041042-1, Bibcode: 2004A&A...421..241S.
- ↑ "20 Boo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=20+Boo.
- ↑ 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.
- ↑ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal 129 (3): 1483–1522, doi:10.1086/427854, Bibcode: 2005AJ....129.1483L.
- ↑ 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
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