HAT-P-20
Star in the constellation Gemini
From Wikipedia, the free encyclopedia
HAT-P-20 is a K-type main-sequence star about 233 light-years away. The star has a strong starspot activity,[5] and its equatorial plane is misaligned by 36+10
−12° with the planetary orbit.[7] Although star with a giant planet on close orbit is expected to be spun-up by tidal forces, only weak indications of tidal spin-up were detected.[10]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Gemini[1] |
| Right ascension | 07h 27m 39.9489s[2] |
| Declination | +24° 20′ 11.516″[2] |
| Apparent magnitude (V) | 11.35[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | K3V[4] |
| Astrometry | |
| Radial velocity (Rv) | -18.559 km/s |
| Proper motion (μ) | RA: −5.104(18) mas/yr[2] Dec.: −96.090(16) mas/yr[2] |
| Parallax (π) | 14.0065±0.0176 mas[2] |
| Distance | 232.9 ± 0.3 ly (71.40 ± 0.09 pc) |
| Details | |
| Mass | 0.798±0.018[5] M☉ |
| Radius | 0.744±0.011[5] R☉ |
| Luminosity | 0.19[6] L☉ |
| Surface gravity (log g) | 4.52±0.09[7] cgs |
| Temperature | 4595±45[7] K |
| Metallicity | 0.22±0.09[7] |
| Rotation | 14.66±0.03 d[5] |
| Rotational velocity (v sin i) | 2.0±0.5[7] km/s |
| Age | 334[8] Myr |
| Other designations | |
| 2MASS J07273995+2420118, Gaia DR2 869913435026514688[9] | |
| Database references | |
| SIMBAD | data |
Planetary system
In 2010 a transiting hot super-Jovian planet was detected.[4] Its equilibrium temperature is 996±19 K.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b | 7.59±0.12 MJ | 0.03671±0.00027 | 2.8753172±0.0000003 | 0.0172±0.0016 | 86.3±0.1 | 0.952±0.017 RJ |
