HD 118203
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 13h 34m 02.5394s |
| Declination | +53° 43′ 42.698″ |
| Apparent magnitude (V) | 8.06 |
| Characteristics | |
| Spectral type | G0V |
| B−V color index | 0.699±0.012 |
| Astrometry | |
| Radial velocity (Rv) | −29.37±0.13 km/s |
| Proper motion (μ) | RA: −85.849(18) mas/yr Dec.: −78.888(20) mas/yr |
| Parallax (π) | 10.8643±0.0180 mas |
| Distance | 300.2 ± 0.5 ly (92.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 3.32 |
| Details | |
| Mass | 1.353±0.006 M☉ |
| Radius | 1.993±0.065 R☉ |
| Luminosity | 4.42±0.02 L☉ |
| Surface gravity (log g) | 4.05±0.04 cgs |
| Temperature | 5,872±20 K |
| Metallicity [Fe/H] | 0.27±0.02 dex |
| Rotational velocity (v sin i) | 7.0 km/s |
| Age | 5.4±0.5 Gyr |
| Other designations | |
| Liesma, BD+54°1609, HD 118203, HIP 66192, SAO 28802, TOI-1271, TIC 286923464, TYC 3850-458-1 | |
| Database references | |
| SIMBAD | The star |
| planet b | |
| Exoplanet Archive | data |
HD 118203 is a star with an orbiting exoplanet located in the northern circumpolar constellation of Ursa Major. It has the proper name Liesma, which means flame, and it is the name of a character from the Latvian poem Staburags un Liesma (Staburags and Liesma). The name was selected in the NameExoWorlds campaign by Latvia, during the 100th anniversary of the IAU.
The apparent visual magnitude of HD 118203 is 8.06, which means it is invisible to the naked eye but it can be seen using binoculars or a telescope. Based on parallax measurements, it is located at a distance of 300 light years from the Sun. The star is drifting closer with a radial velocity of −29 km/s. Based on its position and space velocity this is most likely (97% chance) an older thin disk star. An exoplanet has been detected in a close orbit around the star.
The spectrum of HD 118203 matches a G-type main-sequence star with a class of G0V. It has a low level of chromospheric activity, which means a low level of radial velocity jitter for planet detection purposes. The star has 1.23 times the mass of the Sun and double the Sun's radius. It is around 5.4 billion years old and is spinning with a projected rotational velocity of 7.0 km/s. HD 118203 is radiating 3.8 times the luminosity of the Sun from its photosphere at an effective temperature of 5,741 K.