HD 200964
HD 200964 is a star with a pair of orbiting exoplanets located in the northern constellation of Equuleus. It has an apparent visual magnitude of +6.48, which puts it at the lower limit of visibility to the naked eye, but binoculars would make it easy to see. Based on parallax measurements, the distance to this system is 238 light years, but it is drifting closer with a heliocentric radial velocity of −72.6 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Equuleus |
| Right ascension | 21h 06m 39.842s |
| Declination | +03° 48′ 11.23″ |
| Apparent magnitude (V) | +6.48 |
| Characteristics | |
| Spectral type | G8 IV |
| B−V color index | 0.880±0.009 |
| Astrometry | |
| Radial velocity (Rv) | −72.63±0.03 km/s |
| Proper motion (μ) | RA: 94.748 mas/yr Dec.: 50.418 mas/yr |
| Parallax (π) | 13.7656 ± 0.0275 mas |
| Distance | 236.9 ± 0.5 ly (72.6 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.19 |
| Details | |
| Mass | 1.44±0.09 M☉ |
| Radius | 4.30±0.09 R☉ |
| Luminosity | 13.758±0.064 L☉ |
| Surface gravity (log g) | 3.6±0.1 cgs |
| Temperature | 5,164±44 K |
| Metallicity [Fe/H] | −0.15±0.04 dex |
| Rotational velocity (v sin i) | 2.28±0.5 km/s |
| Age | 3.0±0.6 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a G-type subgiant star with a stellar classification of G8 IV. It is a 3.3 billion year old star that has exhausted the supply of hydrogen at its core and has begun to evolve away from the main sequence, where it was an A-type star. The star has 44% more mass than the Sun and is spinning with a projected rotational velocity of 2.3 km/s. The abundance of iron, an indicator of the star's metallicity, is lower than in the Sun. The star has swelled to 4.3 times the radius of the Sun and it is radiating nearly 14 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,164 K.