Eta Circini
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Circinus |
| Right ascension | 15h 04m 48.18757s |
| Declination | −64° 01′ 52.8641″ |
| Apparent magnitude (V) | 5.17 |
| Characteristics | |
| Evolutionary stage | red giant branch |
| Spectral type | G8 III |
| B−V color index | +0.93 |
| Astrometry | |
| Radial velocity (Rv) | 44.8±0.8 km/s |
| Proper motion (μ) | RA: +102.058 mas/yr Dec.: 8.499 mas/yr |
| Parallax (π) | 11.7561±0.0661 mas |
| Distance | 277 ± 2 ly (85.1 ± 0.5 pc) |
| Absolute magnitude (MV) | +0.52 |
| Details | |
| Mass | 2.9 M☉ |
| Radius | 10 R☉ |
| Luminosity | 78 L☉ |
| Surface gravity (log g) | 2.70 cgs |
| Temperature | 5,250 K |
| Metallicity [Fe/H] | −0.37±0.02 dex |
| Age | 414 Myr |
| Other designations | |
| η Cir, CPD−63°3493, HD 132905, HIP 73776, HR 5593, SAO 253005 | |
| Database references | |
| SIMBAD | data |
Eta Circini, Latinized from η Circini, is the Bayer designation for a solitary star located in the southern constellation of Circinus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.17. The distance to this star, as determined from an annual parallax shift of 11.8 mas, is around 277 light years.
This is an evolved G-type giant star with a stellar classification of G8 III. It is radiating an estimated 78 times the solar luminosity from its outer atmosphere at an effective temperature of 5,250 K.