Sigma1 Gruis
Star in the constellation Grus
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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]
| 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]