| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Indus |
| Right ascension | 21h 50m 0.12s |
| Declination | −64° 42′ 45.1″ |
| Apparent magnitude (V) | 5.6 |
| Characteristics | |
| Evolutionary stage | Horizontal branch |
| Spectral type | K0III |
| B−V color index | 0.99 |
| Astrometry | |
| Radial velocity (Rv) | −0.1701±0.1237 km/s |
| Proper motion (μ) | RA: −0.7032±0.0807 mas/yr Dec.: −37.4432±0.0893 mas/yr |
| Parallax (π) | 9.5919 mas |
| Distance | 343.9±2.6 ly (105.5±0.8 pc) |
| Absolute magnitude (MV) | 0.54 |
| Details | |
| Mass | 2.42±0.27 M☉ |
| Radius | 11.6±1.4 R☉ |
| Luminosity | 74.13+1.12 −1.15 L☉ |
| Surface gravity (log g) | 2.6±0.2 cgs |
| Temperature | 4945±100 K |
| Age | >1 Gyr |
| Other designations | |
| 2MASS J21500013-6442451, FK5 3742, HD 207229, HR 8331, IRAS 21461-6456, PPM 365403, SAO 255080, TIC 406320735, TYC 9119-2234-1 | |
| Database references | |
| SIMBAD | data |
HIP 107773 is a star located 344 light years from Earth in the southern constellation Indus. It is classified as a horizontal branch K-type giant star, having a spectral type K0III and a radius of 11.6 R☉. With an apparent magnitude of 5.6, the star can be faintly seen with the naked eye. It has an exoplanet, HIP 107773 b, a gas giant orbiting it at a distance of 0.72 astronomical units (108,000,000 km), about the same distance from Venus to the Sun.
HIP 107773 is a giant star, having a spectral type K0III, where K0 means it is a K-type star and III (luminosity class) means it is a giant star. The star is in the horizontal branch phase of evolution. HIP 107773 has a radius equivalent to 11.6 solar radii, and a mass equivalent to about 2.4 solar masses. It is cooler than the Sun, having an effective temperature of 4,945 K (4,672 °C). Given the mass and the evolutionary stage of the star, its age is estimated to be at least about one billion years.
HIP 107773 has an exoplanet, HIP 107773 b, discovered in 2015 using the radial velocity method. The planet is classified as a gas giant, having a minimum mass of 2 MJ and an estimated radius of 1.19 RJ. It orbits its star at a distance of 0.72 astronomical units (108,000,000 km), about the same distance as Venus is from the Sun, and completes one orbit every 144 days (0.39 years). Its orbit is almost circular, with an eccentricity of just 0.09.
With a mass of 2.4 M☉, the star HIP 107773 is one of the most massive stars with a close-in planet.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b | ≥1.98±0.21 MJ | 0.72±0.03 | 144.3±0.5 | 0.09±0.06 | — | 1.19 (estimate) RJ |