Pi Andromedae

Pi Andromedae

Location of π Andromedae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Andromeda
Right ascension	00h 36m 52.84926s
Declination	+33° 43′ 09.6384″
Apparent magnitude (V)	4.36 (4.9/5.3)
Characteristics
Spectral type	B5 V (B5 V + B5 V)
U−B color index	–0.55
B−V color index	–0.16
Astrometry
Radial velocity (Rv)	+8.7 km/s
Proper motion (μ)	RA: +14.75 mas/yr Dec.: –3.51 mas/yr
Parallax (π)	5.45 ± 0.31 mas
Distance	600 ± 30 ly (180 ± 10 pc)
Details
Surface gravity (log g)	4.10 cgs
Temperature	15,276 K
Metallicity [Fe/H]	–0.20 dex
Rotational velocity (v sin i)	25 km/s
Other designations
π Andromedae, π And, Pi And, 29 Andromedae, ADS 513, BD+32°101, FK5 18, HD 3369, HIP 2912, HR 154, SAO 54033.

Pi Andromedae (Pi And, π Andromedae, π And) is the Bayer designation for a binary star system in the northern constellation of Andromeda. With an apparent visual magnitude of 4.4, it is visible to the naked eye. It is located approximately 600 light-years (180 parsecs) from Earth.

The pair is classified as a blue-white B-type main sequence dwarf with an apparent magnitude of +4.34. It is a spectroscopic binary with an orbital period of 143.6 days and an eccentricity of 0.56. There is a magnitude 8.6 companion 35.9 arcseconds away. At 55 arcseconds separation is an 11th magnitude companion.

Naming

In Chinese, 奎宿 (Kuí Sù), meaning Legs (asterism), refers to an asterism consisting of π Andromedae, η Andromedae, 65 Piscium, ζ Andromedae, ε Andromedae, δ Andromedae, ν Andromedae, μ Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ¹ Piscium. Consequently, π Andromedae itself is known as 奎宿六 (Kuí Sù liù, English: the Sixth Star of Legs.)

External links

• Image Pi Andromedae