Psi Andromedae

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]

Psi Andromedae

Location of ψ Andromedae (circled)
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(132)[1] mas/yr Dec.: −7.143(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±161[6] 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[7]
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).^[8]