Sigma1 Gruis

Sigma¹ Gruis, a Latinization of σ¹ Gruis, is a star in the constellation Grus. It is a dim, white-hued star near the lower limit for visibility to the naked eye with an apparent visual magnitude of 6.26.^[2] This object is located 229 light-years (70.1 pc) distant from the Sun based on parallax.^[1] The radial velocity of this star is poorly constrained, but it appears to be drifting further away at the rate of +7 km/s.^[3]

For other stars with this Bayer designation, see σ Gruis.

Sigma¹ Gruis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Grus
Right ascension	22h 36m 29.30230s[1]
Declination	−40° 34′ 57.7391″[1]
Apparent magnitude (V)	6.26[2]
Characteristics
Spectral type	A3 Vn[2]
B−V color index	+0.12[2]
Astrometry
Radial velocity (Rv)	+6.9±3.4[3] km/s
Proper motion (μ)	RA: +46.00[4] mas/yr Dec.: −72.64[4] mas/yr
Parallax (π)	14.2651±0.0751 mas[1]
Distance	229 ± 1 ly (70.1 ± 0.4 pc)
Absolute magnitude (MV)	+2.11[5]
Details[6]
Mass	2.00 M☉
Radius	2.0[7] R☉
Luminosity	12[5] L☉
Surface gravity (log g)	4.24±0.14 cgs
Temperature	9,230±314 K
Rotational velocity (v sin i)	163.4±2.0[8] km/s
Age	194 Myr
Other designations
σ1 Gru, CD−41°14959, FK5 3811, HD 214085, HIP 111594, HR 8600, SAO 231211[9]
Database references
SIMBAD	data

This is an A-type main-sequence star with a stellar classification of A2 Vn; a star that is currently fusing its core hydrogen. It has a relatively high rate of spin as indicated by the 'n' suffix, showing a projected rotational velocity of 163 km/s.^[8] This object is 194 million years old with double the mass^[6] and radius of the Sun.^[7] The star is radiating 12^[5] times the luminosity of the Sun from its photosphere at an effective temperature of 9,230 K.^[6] It is a source of X-ray emission, which may indicate it has an unseen stellar companion.^[10]