Eta Andromedae

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**η Andromedae**
Observation data Epoch J2000
Eta Andromeda A/B.
Constellation (pronunciation)	Andromeda
Right ascension	00h 57m 12.4s
Declination	+23° 25' 03.533"'
Apparent magnitude (V)	5.28
Characteristics
Spectral type	G8IIIV
U-B color index	0.69
B-V color index	0.94
Variable type	None
Astrometry
Radial velocity (R_v)	-10.3 km/s
Proper motion (μ)	RA: -43.72 mas/yr Dec.: -46.06 mas/yr
Parallax (π)	13.44 ± 0.75 mas
Distance	240 ± 10 ly (74 ± 4 pc)
Absolute magnitude (M_V)	5.341
Details
Mass	1.1 M_☉
Radius	1.1 R_☉
Surface gravity (log g)	?
Luminosity	1.2 L_☉
Temperature	5.000–6.000 K
Metallicity	?
Rotation	?
Age	? years
Visual binary orbit
Companion	η Andromedae B
Period (P)	0.316769336 yr
Semimajor axis (a)	133.4"
Inclination (i)	232°
Other designations
38 Andromedae, HD 5516, BD +22°153, HIP 4463, SAO 74388, FK5 2060, GC 1136, GC 1136, HR 271.
Database references
SIMBAD	data
Database references
SIMBAD	data

Eta Andromedae (η And / η Andromedae) is a star system in the constellation Andromeda. It is approximately 243 light years from Earth.

The primary component, η Andromedae A, is a yellow G-type giant with an apparent magnitude of +4.40. It is a spectroscopic binary whose components have an orbital period of 115.7 days. It's companion η Andromedae B, is 133.4 arcseconds away and has an apparent magnitude of +11.5.