Canopus

For other uses, see Canopus (disambiguation).
Canopus

An image of Canopus by Expedition 6
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Pronunciation /kəˈnoʊpəs/[1]
Right ascension 06h 23m 57.10988s[2]
Declination −52° 41′ 44.3810″[2]
Apparent magnitude (V) −0.74[3]
Characteristics
Evolutionary stage Blue loop
Spectral type A9 II[4][5]
U−B color index +0.10[3]
B−V color index +0.15[3]
Astrometry
Radial velocity (Rv)20.3±0.5[6] km/s
Proper motion (μ) RA: 19.93[2] mas/yr
Dec.: 23.24[2] mas/yr
Parallax (π)10.55 ± 0.56 mas[2]
Distance310 ± 20 ly
(95 ± 5 pc)
Absolute magnitude (MV)−5.71[7]
Details
Mass9.26–9.81±1.83[8] M☉
Radius73.3±5.2[8] R☉
Luminosity16,600+700
−680[8] L☉
Surface gravity (log g)1.70±0.05[8] cgs
Temperature7,400[9] K
Metallicity [Fe/H]−0.07[7] dex
Rotation≥298 d[10]
Rotational velocity (v sin i)9[9] km/s
Age33–34[8] Myr
Other designations
Suhayl, Suhel, Suhail, α Carinae, CPD−52°1941, FK5 245, GC 8302, HD 45348, HIP 30438, HR 2326, SAO 234480[11]
Database references
SIMBADdata

Canopus is the brightest star in the southern constellation of Carina and the second-brightest star in the night sky. It is also designated α Carinae, which is romanized (transliterated) to Alpha Carinae. With a visual apparent magnitude of −0.74, it is outshone only by Sirius.

Located around 310 light-years from the Sun, Canopus is a bright giant of spectral type A9, so it is essentially white when seen with the naked eye. It has a luminosity over 10,000 times the luminosity of the Sun, is eight times as massive, and has expanded to 71 times the Sun's radius. Its enlarged photosphere has an effective temperature of around 7400 K. Canopus is undergoing core helium burning and is currently in the so-called blue loop phase of its evolution, having already passed through the red-giant branch after exhausting the hydrogen in its core. Canopus is a source of X-rays, which are likely being emitted from its corona.

The prominent appearance of Canopus means it has been the subject of mythological lore among many ancient peoples. Its proper name is generally considered to originate from the mythological Canopus, who was a navigator for Menelaus, king of Sparta. The acronycal rising marked the date of the Ptolemaia festival in Egypt. In ancient India, it was named Agastya after the revered Vedic sage. For Chinese astronomers, it was known as the Old Man of the South Pole. In Islamic astronomy, it is Suhail or Suhayl, a name that is also commonly used to imply rareness of appearance (as the Canopus infrequently appeared to a gazer at Middle Eastern latitutes)

  1. ^ "Canopus". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  2. ^ a b c d e 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. Vizier catalog entry
  3. ^ a b c Ducati, J. R. (2002). "Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D. Vizier catalog entry
  4. ^ Gray, R. O.; Garrison, R. F. (1989). "The early F-type stars – Refined classification, confrontation with Stromgren photometry, and the effects of rotation". Astrophysical Journal Supplement Series. 69: 301. Bibcode:1989ApJS...69..301G. doi:10.1086/191315.
  5. ^ Lopez-Cruz, O.; Garrison, R. F. (1993). "A Spectroscopic Study of High Galactic Latitude F Supergiant Stars". Luminous High-Latitude Stars. The International Workshop on Luminous High-Latitude Stars. 45: 59. Bibcode:1993ASPC...45...59L.
  6. ^ Gontcharov, G. A. (2007). "Pullkovo Compilation of Radial Velocities for 39495 Hipparcos stars in a common system". Astronomy Letters. 32 (1): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169. Vizier catalog entry
  7. ^ a b Cite error: The named reference smiljanic2006 was invoked but never defined (see the help page).
  8. ^ a b c d e Domiciano De Souza, A.; Zorec, J.; Millour, F.; Le Bouquin, J.-B.; Spang, A.; Vakili, F. (2021). "Refined fundamental parameters of Canopus from combined near-IR interferometry and spectral energy distribution". Astronomy & Astrophysics. 654: A19. arXiv:2109.07153. Bibcode:2021A&A...654A..19D. doi:10.1051/0004-6361/202140478. S2CID 237513623.
  9. ^ a b Ayres, Thomas R. (2018). "Cracking the Conundrum of F-supergiant Coronae". The Astrophysical Journal. 854 (2): 95. arXiv:1802.02552. Bibcode:2018ApJ...854...95A. doi:10.3847/1538-4357/aaa6d7. S2CID 119101035.
  10. ^ Cite error: The named reference Testa2004 was invoked but never defined (see the help page).
  11. ^ "alf Car". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-09.