22 Andromedae
Star in the constellation Andromeda
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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 | |
| 22 And, BD+45°17, FK5 4, HD 571, HIP 841, HR 27, SAO 36123, PPM 42645[10] | |
| 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 km/s.[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]