| Observation data EpochJ2000.0 EquinoxJ2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| Right ascension | 09h 08m 00.050s[1] |
| Declination | +29° 39′ 15.24″[1] |
| Apparent magnitude (V) | +5.42[2] |
| Characteristics | |
| Evolutionary stage | red clump[3] |
| Spectral type | G8 III[4] |
| U−Bcolor index | +0.57[2] |
| B−Vcolor index | +0.89[2] |
| Astrometry | |
| Radial velocity (Rv) | −13.90±0.14[5] km/s |
| Proper motion (μ) | RA: −32.199mas/yr[1] Dec.: +2.640mas/yr[1] |
| Parallax (π) | 12.0346±0.1007 mas[1] |
| Distance | 271 ± 2 ly (83.1 ± 0.7 pc) |
| Absolute magnitude (MV) | +0.81[6] |
| Details[5] | |
| Mass | 2.42±0.09 M☉ |
| Radius | 7.76±0.51 R☉ |
| Luminosity | 40 L☉ |
| Surface gravity (log g) | 3.21 cgs |
| Temperature | 5,153 K |
| Metallicity[Fe/H] | −0.06 dex |
| Rotational velocity (v sin i) | 1.95±0.45 km/s |
| Age | 620±60 Myr |
| Other designations | |
| τ Cnc,72 Cancri,BD+30°1817,FK5 2719,HD 78235,HIP 44818,HR 3621,SAO 80650[7] | |
| Database references | |
| SIMBAD | data |
Tau Cancri is a solitary,[4] yellow-huedstar in thezodiacconstellation ofCancer. Its name is aBayer designation that isLatinized from τ Cancri, and abbreviated Tau Cnc or τ Cnc. With anapparent visual magnitude of +5.42,[2] it is faintly visible to thenaked eye. Based upon an annualparallax shift of12.03 mas as seen from Earth,[1] it is located around 272light-years (83 pc) from theEarth. The star is drifting closer to the Sun with a line of sight velocity of −14 km/s.[5]
With an age of about 620[5] million years and astellar classification of G8 III,[4] this is ared-clumpgiant star,[3] which indicates that it hasevolved onto thehorizontal branch and is generating energy throughhelium fusion at its core. It is amicrovariable, showing aluminosity variation of 0.04 inmagnitude.[8] Tau Cancri has an estimated 2.4 times themass of the Sun and 7.8 times theSun's radius. The star radiates 40 times thesolar luminosity from itsphotosphere at aneffective temperature of5,153 K.[5] It is spinning slowly with aprojected rotational velocity of 2 km/s.[5]
