Beta Corvi
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Corvus |
Right ascension | 12h 34m 23.23484s[1] |
Declination | −23° 23′ 48.3374″[1] |
Apparent magnitude (V) | 2.647[2] |
Characteristics | |
Spectral type | G5 II[3] |
U−B color index | +0.586[2] |
B−V color index | +0.898[2] |
R−I color index | +0.44[4] |
Astrometry | |
Radial velocity (Rv) | −7.6[5] km/s |
Proper motion (μ) | RA: +1.11[1] mas/yr Dec.: −56.56[1] mas/yr |
Parallax (π) | 22.39 ± 0.18 mas[1] |
Distance | 146 ± 1 ly (44.7 ± 0.4 pc) |
Absolute magnitude (MV) | –0.61[6] |
Details | |
Mass | 3.342±0.077[7] M☉ |
Radius | 15.841±0.72[7] R☉ |
Luminosity | 164[8] L☉ |
Surface gravity (log g) | 2.86[7] cgs |
Temperature | 5,354[7] K |
Metallicity [Fe/H] | 0.12±0.03[7] dex |
Rotational velocity (v sin i) | 8[9] km/s |
Age | 294±18[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Beta Corvi or β Corvi, officially named Kraz (/ˈkræz/),[11] is the second-brightest star in the southern constellation of Corvus with an apparent visual magnitude of 2.647.[2] Based on parallax measurements obtained during the Hipparcos mission, it is about 146 light-years (45 parsecs) distant from the Sun.
Nomenclature
β Corvi (Latinised to Beta Corvi) is the star's Bayer designation.
In a 1951 publication, Atlas Coeli (Skalnate Pleso Atlas of the Heavens) by Czech astronomer Antonín Bečvář, it bore the name Kraz, whose origin and meaning remain unknown.[12][13][14] In 2016, the IAU organized a Working Group on Star Names (WGSN)[15] to catalog and standardize proper names for stars. The WGSN approved the name Kraz for this star on 1 June 2018 and it is now so included in the List of IAU-approved Star Names.[11]
In Chinese, 軫宿 (Zhěn Sù), meaning Chariot (asterism), refers to an asterism consisting of Beta, Gamma, Epsilon and Delta Corvi.[16] Consequently, Beta Corvi itself is known as 軫宿四 (Zhěn Sù sì, English: the Fourth Star of Chariot).[17]
Properties
Beta Corvi has about 3.3 times the Sun's mass and is roughly 300 million years old,[7] which is old enough for a star of this mass to consume the hydrogen at its core and evolve away from the main sequence. The stellar classification is G5 II,[3] with the luminosity class of 'II' indicating this is a bright giant. The effective temperature of the star's outer envelope is about 5,350 K,[7] which produces a yellow hue common to G-type stars.[18]
Currently, Beta Corvi has expanded to 15.8 times the Sun's size[7] and is emitting about 164 times the luminosity of the Sun.[8] The abundance of elements other than hydrogen or helium, what astronomers term metallicity, is 1.32 times that of the Sun.[7][a]
This is a variable star that ranges in apparent visual magnitude from a low of 2.66 to a high of 2.60.[19]
See also
- List of stars in Corvus
- Beta Leporis, another bright giant star with similar size and spectral type
Notes
- ^ The abundance is estimated by taking [Fe/H] to the power of ten:
10[Fe/H] = 10+0.12 = 1.32
References
- ^ a b c d e van Leeuwen, F. (November 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 Gutierrez-Moreno, Adelina; et al. (1966). "A System of photometric standards". Publications of the Department of Astronomy University of Chile. 1. Publicaciones Universidad de Chile, Department de Astronomy: 1–17. Bibcode:1966PDAUC...1....1G.
- ^ a b Lyubimkov, Leonid S.; et al. (February 2010). "Accurate fundamental parameters for A-, F- and G-type Supergiants in the solar neighbourhood". Monthly Notices of the Royal Astronomical Society. 402 (2): 1369–1379. arXiv:0911.1335. Bibcode:2010MNRAS.402.1369L. doi:10.1111/j.1365-2966.2009.15979.x. S2CID 119096173.
- ^ a b HR 4786, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 9, 2008.
- ^ Evans, D. S. (June 20–24, 1966). Batten, Alan Henry; Heard, John Frederick (eds.). "The Revision of the General Catalogue of Radial Velocities". Determination of Radial Velocities and Their Applications, Proceedings from IAU Symposium No. 30. 30. University of Toronto: International Astronomical Union: 57. Bibcode:1967IAUS...30...57E.
- ^ Takeda, Yoichi; Sato, Bun'ei; Murata, Daisuke (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
- ^ a b c d e f g h i j Gomes da Silva, J.; Santos, N. C.; Adibekyan, V.; Sousa, S. G.; Campante, T. L.; Figueira, P.; Bossini, D.; Delgado-Mena, E.; Monteiro, M. J. P. F. G.; de Laverny, P.; Recio-Blanco, A.; Lovis, C. (2021-02-01). "Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample. I. A catalogue of homogeneous chromospheric activity". Astronomy and Astrophysics. 646: A77. arXiv:2012.10199. Bibcode:2021A&A...646A..77G. doi:10.1051/0004-6361/202039765. ISSN 0004-6361. Beta Corvi's database entry at VizieR.
- ^ a b Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M
- ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago. 239 (1): 1. Bibcode:1970CoAsi.239....1B.
- ^ SV* ZI 946 -- Variable Star, database entry, SIMBAD. Accessed on line September 9, 2008.
- ^ a b "Naming Stars". IAU.org. Retrieved 18 June 2018.
- ^ Kunitzch, Paul; Smart, Tim (2006) [1986]. A Dictionary of Modern Star Names: A Short Guide to 254 Star Names and Their Derivations. Cambridge, Massachusetts: Sky Publishing Corporation. p. 62. ISBN 978-1-931559-44-7.
- ^ Kaler, James B., "KRAZ (Beta Corvi)", Stars, University of Illinois, retrieved 2012-12-28
- ^ Falkner, David E. (2011), The Mythology of the Night Sky: An Amateur Astronomer's Guide to the Ancient Greek and Roman Legends, Patrick Moore's Practical Astronomy, Springer, p. 81, ISBN 978-1-4614-0136-0
- ^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
- ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2011-01-29 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2012-03-18, retrieved 2012-01-16
- ^ Kukarkin, B. V.; et al. (1981), "Nachrichtenblatt der Vereinigung der Sternfreunde e.V. (Catalogue of suspected variable stars)", Nachrichtenblatt der Vereinigung der Sternfreunde, Moscow: Academy of Sciences USSR Shternberg, Bibcode:1981NVS...C......0K
- Articles with Chinese-language sources (zh)
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- G-type bright giants
- Corvus (constellation)
- Bayer objects
- Durchmusterung objects
- Flamsteed objects
- Henry Draper Catalogue objects
- Hipparcos objects
- Bright Star Catalogue objects
- Stars with proper names