Astronomy:Psi Andromedae

Short description: Triple star system in the constellation Andromeda

Psi Andromedae

12px Location of ψ Andromedae (circled)
Observation data Equinox J2000.0]] (ICRS)
Constellation	Andromeda
Right ascension	23h 46m 02.04703s
Declination	+46° 25′ 12.9865″
Apparent magnitude (V)	4.95
Characteristics
Spectral type	G5 Ib + B9
U−B color index	+0.83
B−V color index	+1.085
Astrometry
Radial velocity (Rv)	-23.62 km/s
Proper motion (μ)	RA: 8.446(132) mas/yr Dec.: −7.143(109) mas/yr
Parallax (π)	1.6352 ± 0.1627 mas
Distance	2,000 ± 200 ly (610 ± 60 pc)
Absolute magnitude (MV)	–3.039
Details
ψ And A
Mass	5.4 M☉
Radius	59+8 −10 R☉
Luminosity	1,049±161 L☉
Surface gravity (log g)	1.50 cgs
Temperature	4,276±182 K
Metallicity [Fe/H]	+0.10 dex
Age	79 Myr
B
Mass	2.6 M☉
Temperature	11,000 K
Other designations
20 And, BD+45°4321, FK5 1622, HD 223047, HIP 117221, HR 9003, SAO 53355, PPM 64635
Database references
SIMBAD	data

Psi Andromedae (ψ And, ψ Andromedae) is the Bayer designation for a triple star system in the northern constellation of Andromeda. The combined apparent visual magnitude of this system is 4.95. Based upon parallax measurements, is roughly 2,000 light-years (610 parsecs) from Earth.

The primary component has a stellar classification of G5 Ib, 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.

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).