Eta Virginis
Eta Virginis (η Virginis, abbreviated Eta Vir, η Vir) is a triple star system in the zodiac constellation of Virgo. From parallax measurements taken during the Hipparcos mission it is about 265 light-years (81 parsecs) from the Sun. It has a combined apparent visual magnitude of 3.89, bright enough to be seen with the naked eye in dark skies.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 19m 54.35783s |
| Declination | –00° 40′ 00.5095″ |
| Apparent magnitude (V) | 3.890 |
| Characteristics | |
| Spectral type | A2 V |
| U−B color index | +0.055 |
| B−V color index | +0.029 |
| Astrometry | |
| Radial velocity (Rv) | +2.3 km/s |
| Proper motion (μ) | RA: –57.58 mas/yr Dec.: –25.19 mas/yr |
| Parallax (π) | 12.29 ± 0.45 mas |
| Distance | 265 ± 10 ly (81 ± 3 pc) |
| Absolute magnitude (MV) | −0.66 |
| Orbit | |
| Primary | η Vir Aa |
| Companion | η Vir Ab |
| Period (P) | 71.7916 ± 0.0006 days |
| Semi-major axis (a) | 0.00736 ± 0.0006″ |
| Eccentricity (e) | 0.244 ± 0.007 |
| Inclination (i) | 45.5 ± 0.9° |
| Orbit | |
| Primary | η Vir A |
| Companion | η Vir B |
| Period (P) | 7,896.2 ± 0.2 days |
| Semi-major axis (a) | 0.133 ± 0.001″ |
| Eccentricity (e) | 0.087 ± 0.002 |
| Inclination (i) | 50.6 ± 0.1° |
| Details | |
| η Vir Aa | |
| Mass | 2.5039 ± 0.1246 M☉ |
| Surface gravity (log g) | 3.0 cgs |
| Temperature | 9,333 K |
| Metallicity [Fe/H] | +0.11 dex |
| Rotational velocity (v sin i) | 18 km/s |
| η Vir Ab | |
| Mass | 1.8907 ± 0.0932 M☉ |
| Details | |
| η Vir B | |
| Mass | 1.66 ± 0.16 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The system consists of a binary pair designated Eta Virginis A together with a third companion, Eta Virginis B. A's two components are themselves designated Eta Virginis Aa (officially named Zaniah /ˈzeɪniə/, the traditional name of the system) and Ab.
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