Alpha Corvi

Alpha Corvi
Location of α Corvi (circled in red)
Observation data
Epoch J2000      Equinox ICRS
Constellation Corvus
α Crv A
Right ascension 12h 08m 24.81727s
Declination −24° 43′ 43.9521″
Apparent magnitude (V) 4.03
α Crv B
Right ascension 12h 08m 24.68483s
Declination −24° 43′ 44.3974″
Characteristics
α Crv A
Evolutionary stage main sequence
Spectral type F1 V
U−B color index +0.00
B−V color index +0.34
Variable type Gamma Doradus?
α Crv B
Evolutionary stage main sequence
Spectral type M4 V
Astrometry
α Crv A
Radial velocity (Rv)+3.0 km/s
Proper motion (μ) RA: +96.976 mas/yr
Dec.: −40.023 mas/yr
Parallax (π)66.7696±0.1804 mas
Distance48.8 ± 0.1 ly
(14.98 ± 0.04 pc)
Absolute magnitude (MV)3.25
α Crv B
Proper motion (μ) RA: +23.99 mas/yr
Dec.: −59.66 mas/yr
Parallax (π)66.2258±0.1704 mas
Distance49.2 ± 0.1 ly
(15.10 ± 0.04 pc)
Details
α Crv A
Mass1.34+0.06
−0.04 M☉
Radius1.42±0.03 R☉
Luminosity4.31±0.23 L☉
Surface gravity (log g)4.192±0.030 cgs
Temperature6,985+66
−64 K
Metallicity [Fe/H]−0.04 dex
Rotational velocity (v sin i)16.9±1.5 km/s
Age1.2–1.58 Gyr
Other designations
Alchiba, Al Minliar al Ghurab, Al Chiba, α Crv, 1 Crv, CD−24°10174, GJ 455.3, GJ 9389, HD 105452, HIP 59199, HR 4623, SAO 180505
Database references
SIMBADAlpha Corvi A
Alpha Corvi B

Alpha Corvi is a binary star system in the southern constellation of Corvus. It has the proper name Alchiba, pronounced /ˈælkɪbə/; Alpha Corvi is its Bayer designation. Despite its "alpha" designation, it is the fifth-brightest star in Corvus with an apparent visual magnitude of 4.03. Based on parallax measurements made by the Gaia mission, it is approximately 49 light-years (15 pc) from the Sun.

Nomenclature

α Corvi, which is Latinised to Alpha Corvi and abbreviated Alpha Crv or α Crv, 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) 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'. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name Alchiba for the primary star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.

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), 右轄, yòuxiá was westernized into Yew Hea by R.H. Allen.

Namesake

USS Alchiba (AKA-6) is a former United States Navy ship.

Properties

The two components of Alpha Corvi are separated by roughly 3.1 arcsec. They were found to be a physical pair in 2021. The proper motion differences between both components are much larger than expected for the orbital motion, assuming a total mass of two solar masses and a circular orbit in the plane of the sky. This could indicate that the system is dissolving, or simply that the assumptions are incorrect.

Alpha Corvi A, or Alchiba, has a spectral class F1V, suggesting that it is 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. Alchiba has 34% more mass and is 42% larger than the Sun. It is 4.3 times more luminous and has a surface effective temperature of 6,985 K, 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.

The secondary star, named Alpha Corvi B (or Alchiba B), is a red dwarf with a spectral type of M4V.

See also

References

  1. 1 2 3 4 5 6 7 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.
  2. 1 2 3 4 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. SIMBAD. Bibcode:1986EgUBV........0M.
  3. 1 2 3 4 5 6 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.
  4. 1 2 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.
  5. 1 2 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.
  6. 1 2 3 4 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.
  7. ↑ 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.
  8. ↑ Elgarøy, Øystein; et al. (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.
  9. 1 2 Harada, Caleb K.; et al. (June 2024). "Setting the Stage for the Search for Life with the Habitable Worlds Observatory: Properties of 164 Promising Planet-survey Targets". The Astrophysical Journal Supplement Series. 272 (2). id. 30. arXiv:2401.03047. Bibcode:2024ApJS..272...30H. doi:10.3847/1538-4365/ad3e81.
  10. 1 2 3 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.
  11. ↑ 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.
  12. ↑ "* alf Crv". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2014-05-20.
  13. 1 2 "Naming Stars". IAU.org. Archived from the original on 10 March 2025. Retrieved 16 December 2017.
  14. 1 2 Allen, Richard Hinckley. Star Names — Their Lore and Meaning: Corvus.
  15. ↑ 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.
  16. ↑ "IAU Working Group on Star Names (WGSN)". International Astronomical Union. Archived from the original on 10 June 2016. Retrieved 22 May 2016.
  17. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 22 日 Archived 2021-02-25 at the Wayback Machine
  18. ↑ "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. Archived from the original on 2013-12-03. Retrieved 2012-01-16.