66 Aquarii

This article is about g¹ Aquarii. For other stars with this Bayer designation, see g Aquarii.

66 Aquarii is a single^[11] star in the equatorial constellation of Aquarius. 66 Aquarii is the Flamsteed designation though the star also bears the Bayer designation of g¹ Aquarii.^[12] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.673.^[2] Based upon an annual parallax shift of 7.53 milliarcseconds,^[1] the distance to this star is about 430 light-years (130 parsecs).

66 Aquarii

Location of 66 Aquarii (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Aquarius
Right ascension	22h 43m 35.23307s[1]
Declination	−18° 49′ 49.3557″[1]
Apparent magnitude (V)	4.673[2]
Characteristics
Spectral type	K3 III[3]
U−B color index	+1.549[2]
B−V color index	+1.376[2]
Variable type	suspected[4]
Astrometry
Radial velocity (Rv)	+21.6[5] km/s
Proper motion (μ)	RA: −31.73[1] mas/yr Dec.: −28.54[1] mas/yr
Parallax (π)	7.53±0.26 mas[1]
Distance	430 ± 10 ly (133 ± 5 pc)
Absolute magnitude (MV)	−0.93[6]
Details
Radius	37[7] R☉
Luminosity	434.08[6] L☉
Surface gravity (log g)	2.06[8] cgs
Temperature	4,170[8] K
Metallicity [Fe/H]	−0.23[8] dex
Rotational velocity (v sin i)	10[9] km/s
Other designations
66 Aqr, BD−19°6324, HD 215167, HIP 112211, HR 8649, SAO 165252[10]
Database references
SIMBAD	data

This is an evolved giant star with a stellar classification of K3 III.^[3] It has expanded to 37 times the radius of the Sun^[7] and is radiating 434^[6] times the luminosity of the Sun from its outer envelope at an effective temperature of 4,170 K.^[8] This gives it the orange-hued glow of a K-type star.^[13] It is a suspected variable star that ranges in magnitude between 4.66 and 4.71.^[4]