HAT-P-21
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 11h 25m 05.9859s |
| Declination | +41° 01′ 40.665″ |
| Apparent magnitude (V) | 11.46 |
| Characteristics | |
| Spectral type | G3V |
| Astrometry | |
| Radial velocity (Rv) | −51.87±0.48 km/s |
| Proper motion (μ) | RA: −1.142(17) mas/yr Dec.: 13.523(24) mas/yr |
| Parallax (π) | 3.5190±0.0228 mas |
| Distance | 927 ± 6 ly (284 ± 2 pc) |
| Details | |
| Mass | 0.947±0.042 M☉ |
| Radius | 1.105±0.083 R☉ |
| Luminosity | 1.06+0.20 −0.16 L☉ |
| Surface gravity (log g) | 4.33±0.06 cgs |
| Temperature | 5634±67 K |
| Metallicity | 0.04±0.08 |
| Rotation | 15.88±0.02 d |
| Rotational velocity (v sin i) | 3.5±0.5 km/s |
| Age | 10.2±2.5 Gyr |
| Other designations | |
| Mazaalai, HAT-P-21, TOI-1800, TIC 17993892, TYC 3013-1229-1, GSC 03013-01229, 2MASS J11250598+4101406 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HAT-P-21, also named Mazaalai, is a G-type main-sequence star about 927 light-years away. The star has amount of metals similar to solar abundance. The survey in 2015 has failed to detect any stellar companions. The star is rotating rapidly, being spun up by the tides of giant planet on close orbit.