HD 210702
HD 210702 is a star with an orbiting exoplanet in the northern constellation of Pegasus. It has an apparent visual magnitude of 5.93, which is bright enough that the star is dimly visible to the naked eye. The distance to HD 210702 is 177 light years based on parallax measurements, and it is drifting further away with a radial velocity of 18.5 km/s. It is a probable member of the Ursa Major moving group, an association of co-moving stars.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 22h 11m 51.331s |
| Declination | +16° 02′ 26.00″ |
| Apparent magnitude (V) | 5.93 |
| Characteristics | |
| Evolutionary stage | subgiant |
| Spectral type | K1 III or K1 IV |
| B−V color index | 0.951±0.001 |
| Astrometry | |
| Radial velocity (Rv) | 18.4593±0.0392 km/s |
| Proper motion (μ) | RA: −3.263±0.156 mas/yr Dec.: −17.296±0.036 mas/yr |
| Parallax (π) | 18.4593 ± 0.0392 mas |
| Distance | 176.7 ± 0.4 ly (54.2 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.14 |
| Details | |
| Mass | 1.47±0.04 M☉ |
| Radius | 4.9±0.1 R☉ |
| Luminosity | 12.9±0.1 L☉ |
| Surface gravity (log g) | 3.2200±0.074 cgs |
| Temperature | 4,946±32 K |
| Metallicity [Fe/H] | 0.083±0.027 dex |
| Rotational velocity (v sin i) | 2.50±0.48 km/s |
| Age | 3.1±0.3 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Although a stellar classification of K1 III suggests this is an evolved giant star, it is more likely to be a subgiant star currently at the based of the red giant branch. Currently 3 billion years old, HD 210702 spent its main-sequence life as an A-type star. Consistent with its evolutionary status, it has little or no magnetic activity in its chromosphere. The star has 1.5 times the mass of the Sun and has expanded to 4.9 times the Sun's radius. It is radiating 12.9 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,946 K.