| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 00h45m 40.3578s[1] |
| Declination | +07° 50′ 42.075″[1] |
| Apparent magnitude (V) | 7.83[2] |
| Characteristics | |
| Evolutionary stage | Subgiant[3] |
| Spectral type | K2 IV[citation needed] |
| B−V color index | 0.963±0.017[2] |
| Astrometry | |
| Radial velocity (Rv) | 14.48±0.23[2] km/s |
| Proper motion (μ) | RA: −6.281 mas/yr[1] Dec.: 6.566 mas/yr[1] |
| Parallax (π) | 7.3090 ± 0.0879 mas[1] |
| Distance | 446 ± 5 ly (137 ± 2 pc) |
| Absolute magnitude (MV) | 2.17[2] |
| Details | |
| Mass | 1.61+0.13 −0.12[4] M☉ |
| Radius | 5.15+0.18 −0.17[5] R☉ |
| Luminosity | 15.81[2] L☉ |
| Surface gravity (log g) | 3.24[6] cgs |
| Temperature | 4,966±40[5] K |
| Metallicity [Fe/H] | 0.05±0.10[5] dex |
| Rotational velocity (v sin i) | 1.91±0.25[6] km/s |
| Age | 2.03+0.64 −0.45[5] Gyr |
| Other designations | |
BD+07°104, Gaia DR2 2557541493057378048, HD 4313, HIP 3574, 2MASS J00454035+0750421[7] | |
| Database references | |
| SIMBAD | data |
HD 4313 is a star with an orbiting exoplanetary companion in the constellation of Pisces. It has an apparent visual magnitude of 7.83,[2] which is too faint to be reading visible to the unaided eye. The systam is located at a distance of 446 light years based on parallax, and is drifting further away with a radial velocity of 14.5 km/s.[2] This is a single star, which means it has no binary partners, at least in range of projected separations from 6.85 to 191.78 AU.[8] It hosts an extrasolar planet.
This is an aging K-type star with a mass of nearly twice the Sun, although different methods give mass estimates which differ as much as 0.5 M☉.[5] It is a swollen star with 5.14 times the radius of the Sun, and has a cool effective temperature of 4,966±40k. The "IV" in the spectral class means it's a K-type subgiant[3] star which has exhausted the hydrogen at its core, and cooling and expanding to become a red giant. It is around two billion years in age and is spinning with a projected rotational velocity of 1.9 km/s.
HD 4313 has a superjovian exoplanet orbiting it. This exoplanet was discovered in 2010.[9] It is orbiting the star at a distance of 1.16 AU with an orbital period of 356 days and an eccentricity (ovalness) of 0.15. As the orbital inclination is unknown, only a lower bound on the mass can be determined. The exoplanet has at least 1.2 times the mass of Jupiter.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 1.927±0.090 MJ | 1.157±0.097 | 356.21±0.88 | 0.147±0.047 | — | 1.2 RJ |
