Eta Circini
Star in the constellation Circinus
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Eta Circini, Latinized from η Circini, is the Bayer designation for a solitary[8] star located in the southern constellation of Circinus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.17.[3] The distance to this star, as determined from an annual parallax shift of 11.8 mas, is around 277 light years.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Circinus[1] |
| Right ascension | 15h 04m 48.18757s[2] |
| Declination | −64° 01′ 52.8641″[2] |
| Apparent magnitude (V) | 5.17[3] |
| Characteristics | |
| Evolutionary stage | red giant branch[2] |
| Spectral type | G8 III[4] |
| B−V color index | +0.93[3] |
| Astrometry | |
| Radial velocity (Rv) | 44.8±0.8[5] km/s |
| Proper motion (μ) | RA: +102.058[2] mas/yr Dec.: 8.499[2] mas/yr |
| Parallax (π) | 11.7561±0.0661 mas[2] |
| Distance | 277 ± 2 ly (85.1 ± 0.5 pc) |
| Absolute magnitude (MV) | +0.52[1] |
| Details | |
| Mass | 2.9[2] M☉ |
| Radius | 10[2] R☉ |
| Luminosity | 78[2] L☉ |
| Surface gravity (log g) | 2.70[2] cgs |
| Temperature | 5,250[2] K |
| Metallicity [Fe/H] | −0.37±0.02[6] dex |
| Age | 414[2] Myr |
| Other designations | |
| η Cir, CPD−63°3493, HD 132905, HIP 73776, HR 5593, SAO 253005[7] | |
| Database references | |
| SIMBAD | data |
This is an evolved G-type giant star with a stellar classification of G8 III.[4] It is radiating an estimated 78 times the solar luminosity from its outer atmosphere at an effective temperature of 5,250 K.[6]