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89 Aquarii

89 Aquarii

Location of 89 Aquarii (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Aquarius
Right ascension	23h09m 54.89736s[1]
Declination	–22° 27′ 27.4192″[1]
Apparent magnitude (V)	+4.69[2]
Characteristics
Spectral type	G3 II + A2 V[3]
U−B color index	+0.39[2]
B−V color index	+0.65[2]
Astrometry
Radial velocity (Rv)	-4.8[4] km/s
Proper motion (μ)	RA: +32.61[1] mas/yr Dec.: –9.76[1] mas/yr
Parallax (π)	6.47 ± 0.68 mas[1]
Distance	approx. 500 ly (approx. 150 pc)
Absolute magnitude (MV)	0.1/1.5[5]
Details
89 Aqr A
Mass	2.9[5] M☉
Surface gravity (log g)	3.62[6] cgs
Temperature	5,640[6] K
Metallicity [Fe/H]	+0.27[6] dex
Age	320[5] Myr
89 Aqr B
Mass	2.0[5] M☉
Temperature	8,912[5] K
Other designations
CD–23 17771, HIP 114375, HR 8817, SAO 191687.[7]
89 Aqr A: HD 218640.
89 Aqr B: HD 218641.
Database references
SIMBAD	data

89 Aquarii (abbreviated 89 Aqr) is a binary star^[3] system in the equatorial constellationofAquarius. 89 Aquarii is the Flamsteed designation, though it also bears the Bayer designation c³ Aquarii.^[8] The apparent visual magnitude of +4.69^[2] is bright enough to be seen with the naked eye. Its distance from Earth is roughly 500 light-years (150 pc), based upon parallax measurements with an 11% margin of error.^[1]

The primary component of this system has a magnitude of 5.27 and a stellar classification of G3 II, which suggests this is an evolved star in the bright giant stage. The companion is an A-type main sequence star with a stellar classification of A2 V.^[3] As of 2010, it is located at an angular separation of 0.1843 arcseconds along a position angle of 135.1°.^[9] They orbit each other with an estimated period of 201 years and a semimajor axis of 0.45 arcseconds.^[5]

• Image 89 Aquarii