Theta Aquarii
Theta Aquarii (θ Aquarii, abbreviated Theta Aqr, θ Aqr), officially named Ancha /ˈæŋkə/ (distinguish Ankaa, with the same pronunciation), is a star in the equatorial constellation of Aquarius. Visible to the naked eye at apparent magnitude 4.175, it is located at a distance of around 187 light-years (57 parsecs) from the Sun. Since it is near the ecliptic it can be occulted by the Moon, or very rarely by planets.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 16m 50.03635s |
| Declination | –07° 46′ 59.8480″ |
| Apparent magnitude (V) | 4.175 |
| Characteristics | |
| Spectral type | G8 III–IV |
| U−B color index | +0.818 |
| B−V color index | +0.983 |
| Astrometry | |
| Radial velocity (Rv) | –13.77 ± 0.17 km/s |
| Proper motion (μ) | RA: +118.80 mas/yr Dec.: –22.18 mas/yr |
| Parallax (π) | 17.40 ± 0.23 mas |
| Distance | 187 ± 2 ly (57.5 ± 0.8 pc) |
| Absolute magnitude (MV) | +0.23 |
| Details | |
| Mass | 2.39 to 2.78 M☉ |
| Radius | 12 R☉ |
| Luminosity | 72 to 83 L☉ |
| Surface gravity (log g) | 2.8 cgs |
| Temperature | 4,864 K |
| Metallicity [Fe/H] | +0.01 to +0.09 dex |
| Rotational velocity (v sin i) | 1.6 km/s |
| Age | 437 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.