HAT-P-18
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 05m 23.1475s |
| Declination | +33° 00′ 44.940″ |
| Apparent magnitude (V) | 12.759 |
| Characteristics | |
| Spectral type | K2V |
| Astrometry | |
| Radial velocity (Rv) | -11.83 km/s |
| Proper motion (μ) | RA: −14.002(9) mas/yr Dec.: −36.751(11) mas/yr |
| Parallax (π) | 6.1863±0.0093 mas |
| Distance | 527.2 ± 0.8 ly (161.6 ± 0.2 pc) |
| Details | |
| Mass | 0.750+0.015 −0.014 M☉ |
| Radius | 0.7202+0.0095 −0.01 R☉ |
| Luminosity | 0.27±0.04 L☉ |
| Surface gravity (log g) | 4.599±0.013 cgs |
| Temperature | 4835+39 −35 K |
| Metallicity | 0.044+0.060 −0.051 |
| Rotation | 14.66±0.03 d |
| Rotational velocity (v sin i) | 0.5±0.5 km/s |
| Age | 12.4+4.4 −6.4 Gyr |
| Other designations | |
| Gaia DR2 1334573817793362560, GSC 02594-00646, 2MASS J17052315+3300450 | |
| Database references | |
| SIMBAD | data |
HAT-P-18 is a K-type main-sequence star about 530 light-years away. The star is very old and has a concentration of heavy elements similar to solar abundance. A survey in 2015 detected very strong starspot activity on HAT-P-18.