Pollux (star)
Pollux is the brightest star in the constellation of Gemini. It has the Bayer designation β Geminorum, which is Latinised to Beta Geminorum and abbreviated Beta Gem or β Gem. This is an orange-hued, evolved giant star located at a distance of 34 light-years, making it the closest giant to the Sun. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. In 2006 an extrasolar planet (designated Pollux b or β Geminorum b, later named Thestias) was confirmed to be orbiting it.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Gemini |
| Pronunciation | /ˈpɒləks/ |
| Right ascension | 07h 45m 18.94987s |
| Declination | +28° 01′ 34.3160″ |
| Apparent magnitude (V) | 1.14 |
| Characteristics | |
| Evolutionary stage | Giant star |
| Spectral type | K0 III |
| U−B color index | +0.86 |
| B−V color index | +1.00 |
| V−R color index | +0.75 |
| R−I color index | +0.50 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | +3.23 km/s |
| Proper motion (μ) | RA: −626.55 mas/yr Dec.: −45.80 mas/yr |
| Parallax (π) | 96.54 ± 0.27 mas |
| Distance | 33.78 ± 0.09 ly (10.36 ± 0.03 pc) |
| Absolute magnitude (MV) | +1.08±0.02 |
| Details | |
| Mass | 1.91±0.09 M☉ |
| Radius | 9.06±0.03 R☉ |
| Luminosity | 32.7±1.6 L☉ |
| Surface gravity (log g) | 2.685±0.09 cgs |
| Temperature | 4,586±57 K |
| Metallicity [Fe/H] | –0.07 to +0.19 dex |
| Rotation | 558 days |
| Rotational velocity (v sin i) | 2.8 km/s |
| Age | 724 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
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