Tau Cancri
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| Right ascension | 09h 08m 00.04963s |
| Declination | +29° 39′ 15.2428″ |
| Apparent magnitude (V) | +5.42 |
| Characteristics | |
| Evolutionary stage | red clump |
| Spectral type | G8 III |
| U−B color index | +0.57 |
| B−V color index | +0.89 |
| Astrometry | |
| Radial velocity (Rv) | −13.90±0.14 km/s |
| Proper motion (μ) | RA: −32.51 mas/yr Dec.: +2.79 mas/yr |
| Parallax (π) | 11.92±0.39 mas |
| Distance | 274 ± 9 ly (84 ± 3 pc) |
| Absolute magnitude (MV) | +0.81 |
| Details | |
| 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 | |
| Database references | |
| SIMBAD | data |
Tau Cancri (τ Cancri) is a solitary, yellow-hued star in the zodiac constellation of Cancer. With an apparent visual magnitude of +5.42, it is faintly visible to the naked eye. Based upon an annual parallax shift of 11.92 mas as seen from Earth, it is located around 274 light-years from the Sun.
With an age of about 620 million years and a stellar classification of G8 III, this is a red-clump giant star, which indicates that it has evolved onto the horizontal branch and is generating energy through helium fusion at its core. It is a microvariable, showing a luminosity variation of 0.04 in magnitude. Tau Cancri has an estimated 2.4 times the mass of the Sun and 7.8 times the Sun's radius. The star radiates 40 times the solar luminosity from its photosphere at an effective temperature of 5,153 K.