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.^[7][8]

The apparent visual magnitude of HD 118203 is 8.06,^[2] 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 302 light years from the Sun.^[1] The star is drifting closer with a radial velocity of −29 km/s.^[4] Based on its position and space velocity this is most likely (97% chance) an older thin disk star.^[9] An exoplanet has been detected in a close orbit around the star.^[10]

The spectrum of HD 118203 matches a G-type main-sequence star with a class of G0V.^[3] It has a low level of chromospheric activity, which means a low level of radial velocity jitter for planet detection purposes.^[10] The star has 1.23^[5] 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.^[2] HD 118203 is radiating 3.8 times the luminosity of the Sun from its photosphere at an effective temperature of 5,741 K.^[5]

In 2006, a hot Jupiter candidate was reported in an eccentric orbit around this star. It was discovered using the radial velocity method based on observation of high-metallicity stars begun in 2004.^[10] In 2020, it was found that this is a transiting planet, which allowed the mass and radius of the body to be determined. This exoplanet has more than double the mass of Jupiter and a 13% greater radius. It is named Staburags. The fact that the parent star is among the brighter known planet hosts (as of 2020) makes it an interesting object for further study.^[9]

• List of extrasolar planets