Zeta Gruis
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Grus |
| Right ascension | 23h 00m 52.79777s |
| Declination | −52° 45′ 14.8705″ |
| Apparent magnitude (V) | 4.12 |
| Characteristics | |
| Spectral type | K1 III Fe−1.2 CN−0.5 |
| U−B color index | +0.722 |
| B−V color index | +0.967 |
| Astrometry | |
| Radial velocity (Rv) | −1.1±2.7 km/s |
| Proper motion (μ) | RA: −57.911 mas/yr Dec.: −13.371 mas/yr |
| Parallax (π) | 24.5452±0.5124 mas |
| Distance | 133 ± 3 ly (40.7 ± 0.9 pc) |
| Absolute magnitude (MV) | +1.49 |
| Details | |
| Mass | 1.44±0.06 M☉ |
| Radius | 8.83±0.21 R☉ |
| Luminosity | 39.4±1.7 L☉ |
| Surface gravity (log g) | 2.759±0.077 cgs |
| Temperature | 4,865±22 K |
| Metallicity [Fe/H] | −0.308±0.018 dex |
| Rotational velocity (v sin i) | <1.3 km/s |
| Other designations | |
| ζ Gru, CPD−53°10382, FK5 868, HD 217364, HIP 113638, HR 8747, SAO 247680 | |
| Database references | |
| SIMBAD | data |
Zeta Gruis, Latinised from ζ Gruis, is a solitary star in the southern constellation of Grus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.12. Based upon an annual parallax shift of 24.5 mas as seen from the Earth, the system is located about 133 light-years from the Sun.
This is an evolved K-type giant star with a stellar classification of K1 III Fe−1.2 CN−0.5, where the suffix notation indicates underabundances of iron and cyanogen in the spectrum. Having exhausted the supply of hydrogen at its core, the star has expanded and cooled; at present it has 9 times the girth of the Sun. The star is radiating 39 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,865 K.