HAT-P-15
Star in the constellation Perseus
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HAT-P-15 is a G-type main-sequence star about 630 light-years away. The star is older than Sun yet has a concentration of heavy elements roughly 190% of solar abundance.[5] The star has no noticeable starspot activity.[7]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Perseus[1] |
| Right ascension | 04h 24m 59.5350s[2] |
| Declination | +39° 27′ 38.313″[2] |
| Apparent magnitude (V) | 12.41[3] |
| Characteristics | |
| Spectral type | G5V[citation needed] |
| Variable type | planetary transit[4] |
| Astrometry | |
| Radial velocity (Rv) | 31.21 km/s |
| Proper motion (μ) | RA: 14.233(21)[2] mas/yr[2] Dec.: −9.407(15)[2] mas/yr[2] |
| Parallax (π) | 5.1856±0.0166 mas[2] |
| Distance | 629 ± 2 ly (192.8 ± 0.6 pc) |
| Details[5] | |
| Mass | 1.013±0.043 M☉ |
| Radius | 1.080±0.039 R☉ |
| Luminosity | 1.00±0.11 L☉ |
| Surface gravity (log g) | 4.38±0.03 cgs |
| Temperature | 5684±25 K |
| Metallicity | 0.272±0.031 |
| Rotational velocity (v sin i) | 2.0±0.5 km/s |
| Age | 6.8+2.5 −1.6 Gyr |
| Other designations | |
| Berehynia, TYC 2883-1687-1, GSC 02883-01687, 2MASS J04245952+3927382, Gaia DR3 179498266829041664[6] | |
| Database references | |
| SIMBAD | data |
The spectroscopic survey in 2015 have failed to find any stellar companions to it,[8] yet imaging survey have identified a possibly two companion red dwarf stars at projected separations 1210 and 1370 AU, respectively.[9]
The star was named Berehynia in December 2019 by Ukrainian amateur astronomers.[10]
Planetary system
In 2010 a transiting hot superjovian planet b (named Tryzub in 2019[10]) was detected. It has an equilibrium temperature of 904±20 K.[4] An orbital simulation shows that any planets inward of the orbit of b would spiral inward and be destroyed within a time-span of less than a billion years.[11] The planetary orbit is well aligned with the equatorial plane of the star, misalignment equal to 13±6 degrees.[12]

| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b / Tryzub | 1.946±0.066 MJ | 0.0964±0.0014 | 10.863502±0.000027 | 0.19±0.019 | 89.1±0.2 | 1.072±0.043 RJ |