Beta Cancri
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 16m 30.92099s |
| Declination | +09° 11′ 07.9582″ |
| Apparent magnitude (V) | 3.50 to 3.58 |
| Characteristics | |
| Spectral type | K4III Ba1 |
| U−B color index | +1.77 |
| B−V color index | +1.48 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | 22.94 km/s |
| Proper motion (μ) | RA: −46.82 mas/yr Dec.: −49.24 mas/yr |
| Parallax (π) | 10.75±0.19 mas |
| Distance | 303 ± 5 ly (93 ± 2 pc) |
| Absolute magnitude (MV) | −1.218 |
| Details | |
| Mass | 1.7±0.1 M☉ |
| Radius | 51.7±1 R☉ |
| Luminosity | 677±41 L☉ |
| Surface gravity (log g) | 1.28±0.04 cgs |
| Temperature | 4,094±53 K |
| Metallicity [Fe/H] | −0.29±0.06 dex |
| Rotational velocity (v sin i) | 3.7±0.8 km/s |
| Age | 1.85±0.34 Gyr |
| Other designations | |
| Tarf, β Cancri, 17 Cancri, BD+09°1917, FK5 312, GC 11254, HD 69267, HIP 40526, HR 3249, SAO 116569, ADS 6704, CCDM 08165+0911, WDS J08165+0911A | |
| Database references | |
| SIMBAD | data |
Beta Cancri is the brightest star in the zodiacal constellation of Cancer. The star has the proper name Tarf, pronounced /ˈtɑːrf/; Beta Cancri is its Bayer designation. It is visible to the naked eye with an apparent visual magnitude of +3.5, and has an absolute magnitude of −1.2. Based on parallax measurements, it is 303 light-years distant from the Solar System. It is drifting further away with a line of sight velocity of 23 km/s. An exoplanet, designated Beta Cancri b, is believed to be orbiting the star.
Beta Cancri has a companion listed and together they are designated WDS J08165+0911. As the primary, Beta Cancri bears the designation WDS J08165+0911A. The companion is designated WDS J08165+0911B.