Summary
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]
| 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] |
| Characteristics | |
| Spectral type | F5 II[3] or F5 Ib–II metal-weak[4] |
| B−V color index | +0.04[2] |
| Astrometry | |
| 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 mas[1] |
| Distance | approx. 1,500 ly (approx. 450 pc) |
| Absolute magnitude (MV) | −3.51[6] |
| Details | |
| Mass | 6.1±0.4[3] M☉ |
| Radius | 17[7] R☉ |
| Luminosity | 1,436[8] L☉ |
| Surface gravity (log g) | 2.10±0.08[3] cgs |
| Temperature | 6,270±150[3] K |
| Metallicity [Fe/H] | −0.09±0.05[2] dex |
| Rotational velocity (v sin i) | 46[9] km/s |
| Age | 62[3] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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]
References edit
- ^ 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.
- ^ 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, S2CID 119258214.
- ^ 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, S2CID 119096173.
- ^ 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.
- ^ 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, S2CID 59451347, A61.
- ^ 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, S2CID 118683158.
- ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (2) (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ 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, S2CID 111387483.
- ^ 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.
- ^ "22 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 21, 2018.
- ^ 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, S2CID 14878976.