Xi Geminorum
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Gemini |
| Right ascension | 06h 45m 17.36432s |
| Declination | +12° 53′ 44.1311″ |
| Apparent magnitude (V) | 3.35 |
| Characteristics | |
| Spectral type | F5 IV-V |
| U−B color index | +0.06 |
| B−V color index | +0.43 |
| Astrometry | |
| Radial velocity (Rv) | +25.6 km/s |
| Proper motion (μ) | RA: –115.73 mas/yr Dec.: –190.55 mas/yr |
| Parallax (π) | 55.56±0.19 mas |
| Distance | 58.7 ± 0.2 ly (18.00 ± 0.06 pc) |
| Absolute magnitude (MV) | 2.14 |
| Details | |
| Mass | 1.706 ± 0.012 M☉ |
| Radius | 2.710 ± 0.021 R☉ |
| Luminosity | 11.574 ± 0.238 L☉ |
| Surface gravity (log g) | 3.81 ± 0.02 cgs |
| Temperature | 6,480 ± 39 K |
| Metallicity [Fe/H] | 0.00 ± 0.01 dex |
| Rotational velocity (v sin i) | 66.1 ± 3.3 km/s |
| Age | 1.5 Gyr |
| Other designations | |
| 31 Geminorum, HR 2484, HD 48737, BD+13°1396, FK5 256, HIP 32362, SAO 96074 | |
| Database references | |
| SIMBAD | data |
Xi Geminorum (ξ Geminorum, abbreviated Xi Gem, ξ Gem), formally named Alzirr /ˈælzər/, is a star in the zodiac constellation of Gemini. It forms one of the four feet of the outline demarcating the Gemini twins. The star has an apparent visual magnitude of 3.35, which is bright enough for it to be seen with the naked eye. From stellar parallax measurements, its distance from the Sun can be estimated as 58.7 light-years (18.0 parsecs).