Alpha Corvi (α Corvi, abbreviated Alpha Crv, α Crv), also named Alchiba /ˈælkɪbə/,[12] is an F-type main-sequence star and, despite its "alpha" designation, is the fifth-brightest star in the constellation of Corvus. Based on parallax measurements made by the Gaia mission, it is approximately 49 light-years from the Sun.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Corvus |
| Right ascension | 12h 08m 24.81727s[1] |
| Declination | −24° 43′ 43.9521″[1] |
| Apparent magnitude (V) | 4.03[2] |
| Characteristics | |
| Spectral type | F1 V[3] + M4 V[4] |
| U−B color index | +0.00[2] |
| B−V color index | +0.34[2] |
| Variable type | Gamma Doradus?[5] |
| Astrometry | |
| Radial velocity (Rv) | +3.0[6] km/s |
| Proper motion (μ) | RA: +96.976 mas/yr[1] Dec.: −40.023 mas/yr[1] |
| Parallax (π) | 66.7696 ± 0.1804 mas[1] |
| Distance | 48.8 ± 0.1 ly (14.98 ± 0.04 pc) |
| Absolute magnitude (MV) | 3.25[7] |
| Details | |
| Mass | 1.32[8] M☉ |
| Radius | 1.373[9] R☉ |
| Luminosity | 4.145[9] L☉ |
| Surface gravity (log g) | 4.27[8] cgs |
| Temperature | 7,035[9] K |
| Metallicity [Fe/H] | −0.04[8] dex |
| Rotational velocity (v sin i) | 16.9 ± 1.5[10] km/s |
| Age | 1.2–1.58[8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Nomenclature
editα Corvi (Latinised to Alpha Corvi) is the star's Bayer designation.
It bore the traditional names Al Chiba (Arabic: ألخبا al-xibā, 'tent') and Al Minliar al Ghurab (Arabic منقار الغراب al-manxar al-ghurab)[13] or Minkar al Ghurab. The latter appeared in the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, which was translated into Latin as Rostrum Corvi, 'beak of the crow'.[14] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[15] to catalogue and standardize proper names for stars. The WGSN approved the name Alchiba for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.[12]
In Chinese astronomy, Alchiba is called 右轄, Pinyin: yòuxiá, meaning 'right linchpin', because it stands alone in the 'right linchpin' asterism, Chariot mansion (see: Chinese constellations),[16] 右轄, yòuxiá was westernized into Yew Hea by R.H. Allen.[13]
Namesake
editUSS Alchiba (AKA-6) is a former United States Navy ship.
Properties
editAlchiba has a spectral class F1V,[3] classifying it as a main sequence star fusing hydrogen into helium at its core. This star exhibits periodic changes in its spectrum over a three-day period, which suggests it is either a spectroscopic binary or (more likely) a pulsating Gamma Doradus-type variable.[5] Alchiba has 32% more mass[8] and is 37% larger than the Sun. It is four times more luminous and has a surface effective temperature of 7,035 K,[9] giving it the yellow-white hue of an F-type star. The abundance of chemical elements other than hydrogen and helium, what astronomers name metallicity, is slightly lower than that of the Sun.[8]
Alpha Corvi has a common proper motion companion, named Alpha Corvi B (or Alchiba B), located about 3.1 arcsec away. It is a red dwarf with a spectral type of M4V.[4]
See also
editReferences
edit- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ^ a b Scholz, Ralf-Dieter (2021). "Gaia EDR3 Confirms a Red Dwarf Companion of the nearby F1 Star HD 105452 and Reveals a New Brown Dwarf Companion of the M4.5 Dwarf SCR J1214-2345". Research Notes of the AAS. 5 (3): 40. arXiv:2103.00144. Bibcode:2021RNAAS...5...40S. doi:10.3847/2515-5172/abea23. S2CID 232075955. 40.
- ^ a b Fuhrmann, K.; Chini, R. (2012). "Multiplicity among F-type Stars". The Astrophysical Journal Supplement. 203 (2): 20. Bibcode:2012ApJS..203...30F. doi:10.1088/0067-0049/203/2/30. 30.
- ^ Nordström, B.; et al. (2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ~14000 F and G dwarfs", Publications of the Astronomical Society of Australia, 21 (2): 129–133, arXiv:0811.3982, Bibcode:2004PASA...21..129N, doi:10.1071/AS04013, S2CID 123457673.
- ^ Elgarøy, Øystein; Engvold, Oddbjørn; Lund, Niels (March 1999), "The Wilson-Bappu effect of the MgII K line - dependence on stellar temperature, activity and metallicity", Astronomy and Astrophysics, 343: 222–228, Bibcode:1999A&A...343..222E.
- ^ a b c d e f Luck, R. Earle (2017-01-01). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 21. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. ISSN 0004-6256.
- ^ a b c d Schofield, Mathew; Chaplin, William J.; Huber, Daniel; Campante, Tiago L.; Davies, Guy R.; Miglio, Andrea; Ball, Warrick H.; Appourchaux, Thierry; Basu, Sarbani; Bedding, Timothy R.; Christensen-Dalsgaard, Jørgen; Creevey, Orlagh; García, Rafael A.; Handberg, Rasmus; Kawaler, Steven D. (2019-03-01). "The Asteroseismic Target List for Solar-like Oscillators Observed in 2 minute Cadence with the Transiting Exoplanet Survey Satellite". The Astrophysical Journal Supplement Series. 241 (1): 12. arXiv:1901.10148. Bibcode:2019ApJS..241...12S. doi:10.3847/1538-4365/ab04f5. ISSN 0067-0049. Alchiba's database entry at VizieR.
- ^ Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
- ^ "* alf Crv". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2014-05-20.
{{cite web}}: CS1 maint: postscript (link) - ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017.
- ^ a b Allen, Richard Hinckley, Star Names — Their Lore and Meaning: Corvus.
- ^ Knobel, E. B. (June 1895), "Al Achsasi Al Mouakket, on a catalogue of stars in the Calendarium of Mohammad Al Achsasi Al Mouakket", Monthly Notices of the Royal Astronomical Society, 55: 429, Bibcode:1895MNRAS..55..429K, doi:10.1093/mnras/55.8.429.
- ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
- ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 22 日
External links
edit- Alpha Corvi by Professor Jim Kaler.