Psi Andromedae
Triple star system in the constellation Andromeda
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Psi Andromedae (ψ And, ψ Andromedae) is the Bayer designation for a triple star[4] system in the northern constellation of Andromeda. The combined apparent visual magnitude of this system is 4.95.[2] Based upon parallax measurements, is roughly 2,000 light-years (610 parsecs) from Earth.[1]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 46m 02.04703s[1] |
| Declination | +46° 25′ 12.9865″[1] |
| Apparent magnitude (V) | 4.95[2] |
| Characteristics | |
| Spectral type | G5 Ib[3] + B9[4] |
| U−B color index | +0.83[2] |
| B−V color index | +1.085[3] |
| Astrometry | |
| Radial velocity (Rv) | −23.62[3] km/s |
| Proper motion (μ) | RA: +8.446±0.132[1] mas/yr Dec.: −7.143±0.109[1] mas/yr |
| Parallax (π) | 1.6352±0.1627 mas[1] |
| Distance | 2,000 ± 200 ly (610 ± 60 pc) |
| Absolute magnitude (MV) | –3.039[3] |
| Details | |
| ψ And A | |
| Mass | 5.4[4] M☉ |
| Radius | 59+8 −10[5] R☉ |
| Luminosity | 1,049.5±0.2[5] L☉ |
| Surface gravity (log g) | 1.50[3] cgs |
| Temperature | 4,276±182[5] K |
| Metallicity [Fe/H] | +0.10[3] dex |
| Age | 79[4] Myr |
| B | |
| Mass | 2.6[4] M☉ |
| Temperature | 11,000[4] K |
| Other designations | |
| 20 And, BD+45°4321, FK5 1622, HD 223047, HIP 117221, HR 9003, SAO 53355, PPM 64635[6] | |
| Database references | |
| SIMBAD | data |
The primary component has a stellar classification of G5 Ib,[3] which matches the spectrum of an evolved supergiant star. It forms a pair with a star of type B9 with an unknown luminosity class separated by 0.28 arcseconds. A third component has a separation of 0.14 arcseconds. Details of the orbital arrangement remain uncertain.[4]
Naming
In Chinese, 螣蛇 (Téng Shé), meaning Flying Serpent, refers to an asterism consisting of ψ Andromedae, α Lacertae, 4 Lacertae, π2 Cygni, π1 Cygni, HD 206267, ε Cephei, β Lacertae, σ Cassiopeiae, ρ Cassiopeiae, τ Cassiopeiae, AR Cassiopeiae, 9 Lacertae, 3 Andromedae, 7 Andromedae, 8 Andromedae, λ Andromedae, κ Andromedae and ι Andromedae,. Consequently, the Chinese name for ψ Andromedae itself is 螣蛇二十 (Téng Shé èrshí, English: the Twentieth of Flying Serpent).[7]