22 Andromedae

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22 Andromedae
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 00h 10m 19.24653s[1]
Declination +46° 04′ 20.1704″[1]
Apparent magnitude (V) 5.04[2]
Spectral type F5 II[3] or F5 Ib–II metal-weak[4]
B−V color index +0.04[2]
Radial velocity (Rv)−8.2±2.2[5] km/s
Proper motion (μ) RA: 5.472[1] mas/yr
Dec.: 0.086[1] mas/yr
Parallax (π)2.2233 ± 0.3881[1] mas
Distanceapprox. 1,500 ly
(approx. 450 pc)
Absolute magnitude (MV)−3.51[6]
Mass6.1±0.4[3] M
Radius17[7] R
Luminosity1,436[8] L
Surface gravity (log g)2.10±0.08[3] cgs
Temperature6,270±150[3] K
Metallicity [Fe/H]−0.09±0.05[2] dex
Rotational velocity (v sin i)46[9] km/s
Age62[3] Myr
Other designations
22 And, BD+45° 17, FK5 4, HD 571, HIP 841, HR 27, SAO 36123[10]
Database references

22 Andromedae, abbreviated 22 And, is a single[11] star in the constellation Andromeda. 22 Andromedae is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 5.04.[2] The distance to 22 And can be estimated from its annual parallax shift of just 2.2 mas,[1] which shows it to be around 1,500 light years away. It is moving closer to the Earth with a heliocentric radial velocity of −8.2 km/s.[5]

This is a bright giant with a stellar classification of F5 II.[3] Gray et al. (2001) classify it as F5 Ib–II metal-weak, with the metallic lines matching a class of F0 whereas hydrogen lines match an F5.[4] It is around 62[3] million years old with a projected rotational velocity of 46.[9] The star has six[3] times the mass of the Sun and has expanded to about 17[7] times the Sun's radius. It is radiating 1,436[8] times the Sun's luminosity from its photosphere at an effective temperature of 6,270 km/s.[3]


  1. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
  2. ^ a b c d Soubiran, Caroline; et al. (2016), "The PASTEL catalogue: 2016 version", Astronomy & Astrophysics, 591: A118, arXiv:1605.07384, Bibcode:2016A&A...591A.118S, doi:10.1051/0004-6361/201628497.
  3. ^ a b c d e f g h i Lyubimkov, Leonid S.; et al. (2010), "Accurate fundamental parameters for A-, F- and G-type Supergiants in the solar neighbourhood", Monthly Notices of the Royal Astronomical Society, 402 (2): 1369–79, arXiv:0911.1335, Bibcode:2010MNRAS.402.1369L, doi:10.1111/j.1365-2966.2009.15979.x.
  4. ^ a b Gray, R. O.; et al. (2001), "The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars", The Astronomical Journal, 121 (4): 2148, Bibcode:2001AJ....121.2148G, doi:10.1086/319956.
  5. ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  6. ^ Kovtyukh, V. V.; et al. (2012), "Accurate luminosities from the oxygen λ7771-4 Å triplet and the fundamental parameters of F-G supergiants", Monthly Notices of the Royal Astronomical Society, 423 (4): 3268–3273, arXiv:1204.4115, Bibcode:2012MNRAS.423.3268K, doi:10.1111/j.1365-2966.2012.21117.x, ISSN 0035-8711.
  7. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  8. ^ a b Hohle, M.M.; et al. (2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355.
  9. ^ a b Danziger, I. J.; Faber, S. M. (May 1972), "Rotation of evolving A and F stars", Astronomy and Astrophysics, 18: 428, Bibcode:1972A&A....18..428D.
  10. ^ "22 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 21, 2018.
  11. ^ 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.