HAT-P-12

HAT-P-12 is a G-type main-sequence star located approximately 415 light-years away in the constellation Canes Venatici. It is notable for hosting the exoplanet HAT-P-12b, a transiting hot Jupiter discovered in 2009 by the Hungarian Automated Telescope Network (HATNet) project.

Stellar Characteristics:

HAT-P-12 is somewhat smaller and less massive than the Sun. Its effective temperature is around 5198 Kelvin, making it slightly cooler. The star's estimated age is several billion years. Metallicity, a measure of elements heavier than hydrogen and helium, is relatively low compared to the Sun.

Planetary System:

HAT-P-12b is a gas giant exoplanet orbiting extremely close to HAT-P-12, completing an orbit in approximately 3.2 days. This proximity results in a high equilibrium temperature for the planet. HAT-P-12b is notable for having a relatively low density for a hot Jupiter, significantly lower than Jupiter itself. The planet's low density poses challenges for planetary formation and evolution models.

Discovery:

HAT-P-12b was discovered using the transit method, where periodic dips in the star's light indicate a planet passing in front of it. The HATNet project, a network of small, wide-field telescopes, monitors large areas of the sky to identify potential transiting exoplanets. Follow-up radial velocity measurements were used to confirm the planet's existence and determine its mass.