20 Cancri
20 Cancri is an astrometric binary star system in the constellation Cancer, located about 372 light-years away from the Sun. This system has the Bayer designation d1 Cancri; 20 Cancri is the Flamsteed designation. It is just visible to the naked eye under good viewing conditions, appearing as a dim, white-hued star with an apparent visual magnitude of 5.94. The pair are moving further from the Earth with a heliocentric radial velocity of +36 km/s, and are members of the Hyades Supercluster.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 23m 21.84287s |
| Declination | +18° 19′ 55.7825″ |
| Apparent magnitude (V) | 5.94 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | A9 V |
| B−V color index | 0.175 |
| Astrometry | |
| Radial velocity (Rv) | +35.8±2.9 km/s |
| Proper motion (μ) | RA: −51.953 mas/yr Dec.: −19.416 mas/yr |
| Parallax (π) | 8.7606 ± 0.0986 mas |
| Distance | 372 ± 4 ly (114 ± 1 pc) |
| Absolute magnitude (MV) | +0.63 |
| Details | |
| Mass | 2.41±0.10 M☉ |
| Radius | 3.7 R☉ |
| Luminosity | 59.9+19.9 −15.0 L☉ |
| Surface gravity (log g) | 3.62 cgs |
| Temperature | 7,907±73 K |
| Metallicity [Fe/H] | −0.30 dex |
| Rotational velocity (v sin i) | 50 km/s |
| Age | 700 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The visible component of this system is an ordinary A-type main-sequence star with a stellar classification of A9 V, which indicates it is generating energy by hydrogen fusion at its core. It has 2.4 times the mass of the Sun and is radiating 60 times the Sun's luminosity from its photosphere at an effective temperature of 7,907 K.