| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Major[1] |
| Right ascension | 08h 39m 31.8072s[2] |
| Declination | +47° 21′ 07.274″[2] |
| Apparent magnitude (V) | 10.62 |
| Characteristics | |
| Spectral type | G4V[3] |
| Variable type | Planetary transit[3] |
| Astrometry | |
| Radial velocity (Rv) | 14.69 ± 0.68[3] km/s |
| Proper motion (μ) | RA: −24.060(16)mas/yr[2] Dec.: −26.218(17)mas/yr[2] |
| Parallax (π) | 4.0750±0.0186 mas[2] |
| Distance | 800 ± 4 ly (245 ± 1 pc) |
| Details | |
| Mass | 1.261+0.029 −0.023[4] M☉ |
| Radius | 1.73+0.10 −0.09[4] R☉ |
| Surface gravity (log g) | 4.13 ± 0.04[5] cgs |
| Temperature | 5720 ± 69[5] K |
| Metallicity[Fe/H] | 0.46 ± 0.07[5] dex |
| Rotational velocity (v sin i) | 3.1 ± 0.9[5] km/s |
| Age | 5 Gyr |
| Other designations | |
| TYC 3416-543-1,GSC 03416-00543,2MASS J08393180+4721073[6] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HAT-P-13, also known asGSC 03416-00543, is aG-type main sequencestar approximately 800light-years away in theconstellationUrsa Major. In 2009 it was discovered that this star is orbited by two massiveplanets, the innermost of whichtransits the star. This was the first known example of an extrasolar transiting planet with an additional planet in the same system.[3]
In 2015, a spectroscopic study have revealed a very strongstarspot activity of the HAT-P-13 star.[7]
As of 2009, HAT-P-13 has been confirmed to have twoextrasolar planets orbiting it. The inner planet was discovered by the "transit method" and the outer planet was found through theradial velocity method. A search for transits by HAT-P-13c was negative, however only 72% of the possible transit configurations could be ruled out.[8] HAT-P-13 was the first star to have a transiting planet and an additional planet on a known orbit.[3]HAT-P-7 and other planets are known to have additional companions, but there is not enough data to characterize the system.OGLE-TR-111 has one confirmed transiting planet, and one unconfirmed transiting planet.
The innermost planet,HAT-P-13b, has a mass around that ofJupiter and orbits its sun roughly every three days. This classifies the planet as ahot Jupiter, with temperatures exceeding 1000kelvins. The second companion,HAT-P-13c, has a mass over 15 Jupiters. Because of its mass, this companion could either be a massive planet or a low massbrown dwarf. Either way, HAT-P-13 c orbits its sun every 446 days in a highly eccentric orbit. Radial velocity measurements also suggest the existence of a third more distant companion in the system. This may be an additional planet, or it may be a brown dwarf or even a small star.[9]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.906±0.024 MJ | 0.04313+0.00033 −0.00026 | 2.91624039±0.00000081 | 0.0093+0.0044 −0.0016 | 82.2+0.6 −0.8° | 1.487±0.038 RJ |
| c | ≥14.28 ± 0.28 MJ | 1.188+0.018 −0.033 | 445.81±0.10 | 0.6616 ± 0.0054 | — | — |
