HD 115310 is a G-type main-sequence star located approximately 418 light-years (128 parsecs) from Earth in the constellation Centaurus. The "HD" designation indicates its inclusion in the Henry Draper Catalogue, a comprehensive astronomical star catalogue published by the Harvard College Observatory between 1918 and 1924.
Characteristics HD 115310 is classified as a G0V star, meaning it is a yellow-white dwarf star that is slightly hotter and more massive than our Sun. Its apparent visual magnitude is approximately 8.04, making it too faint to be seen with the naked eye but easily observable with a small telescope. Its surface temperature is estimated to be around 5,900 Kelvin.
Planetary System HD 115310 is notable for hosting a multi-planetary system with at least three confirmed exoplanets, all discovered using the radial velocity method, which detects the slight wobble in a star caused by the gravitational pull of orbiting planets. All three planets are super-Jupiters, meaning they have masses significantly greater than that of Jupiter.
The confirmed planets are:
- HD 115310 b: This planet has a minimum mass of approximately 6.7 Jupiter masses and orbits its star every 527 days (about 1.4 years) at an average distance of roughly 1.2 astronomical units (AU).
- HD 115310 c: With a minimum mass of approximately 18.7 Jupiter masses, this exoplanet completes an orbit around HD 115310 every 1,419 days (about 3.9 years) at an average distance of approximately 2.4 AU. Due to its significant mass, it lies on the boundary often considered between a large planet and a brown dwarf.
- HD 115310 d: The outermost known planet in the system, HD 115310 d, has a minimum mass of about 13.9 Jupiter masses. It has an orbital period of approximately 3,046 days (about 8.3 years) and orbits at an average distance of around 4.0 AU from its host star.
The discovery of this multiple giant planet system provides valuable data for understanding the formation and evolution of planetary systems, particularly those with massive gas giants orbiting within various distances from their parent stars.