WASP-21
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 23h 09m 58.25s |
| Declination | +18° 23′ 45.9″ |
| Apparent magnitude (V) | 11.58±0.08 |
| Characteristics | |
| Evolutionary stage | subgiant |
| Spectral type | G3V |
| Astrometry | |
| Radial velocity (Rv) | −89.21±0.46 km/s |
| Proper motion (μ) | RA: +17.567(21) mas/yr Dec.: +18.639(18) mas/yr |
| Parallax (π) | 3.9089±0.0197 mas |
| Distance | 834 ± 4 ly (256 ± 1 pc) |
| Absolute magnitude (MV) | 4.97 |
| Details | |
| Mass | 0.89±0.071 M☉ |
| Radius | 1.136±0.049 R☉ |
| Luminosity | 1.4 L☉ |
| Surface gravity (log g) | 4.277±0.025 cgs |
| Temperature | 5,800±100 K |
| Metallicity | −0.4±0.1 |
| Metallicity [Fe/H] | −0.46±0.11 dex |
| Rotational velocity (v sin i) | 1.5±0.6 km/s |
| Age | 12±5 Gyr |
| Other designations | |
| Tangra, TOI-5963, TIC 436478932, WASP-21, GSC 01715-00679, 2MASS J23095825+1823459 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
WASP-21, also named Tangra, is a G-type star (spectral type G3V) that has reached the end of its main sequence lifetime. It lies approximately 834 light-years away, in the constellation of Pegasus. The star is relatively metal-poor, having 40% of heavy elements compared to the Sun. Kinematically, WASP-21 belongs to the thick disk of the Milky Way. It has an exoplanet named WASP-21b.
A survey in 2012 failed to find any stellar companions to WASP-21.