66 Cancri is a binary star[9] system near the northern border of the zodiac constellation of Cancer, located 474 light years away from the Sun. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.87.[2] The pair are moving closer to the Earth with a heliocentric radial velocity of −13 light years.[6] As of 2003, the magnitude 8.56 companion was located at an angular separation of 4.43″ along a position angle of 134° from the primary.[9]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cancer |
Right ascension | 09h 01m 24.13000s[1] |
Declination | +32° 15′ 08.2666″[1] |
Apparent magnitude (V) | 5.870[2] (5.95 + 8.56)[3] |
Characteristics | |
Evolutionary stage | main sequence[4] |
Spectral type | A2 V[2] |
B−V color index | 0.088±0.007[5] |
Astrometry | |
Radial velocity (Rv) | −12.8±2.9[6] km/s |
Proper motion (μ) | RA: +0.48[7] mas/yr Dec.: +0.34[7] mas/yr |
Parallax (π) | 6.8850 ± 0.1020 mas[1] |
Distance | 474 ± 7 ly (145 ± 2 pc) |
Absolute magnitude (MV) | 0.14[5] |
Details | |
Mass | 2.73±0.11[4] M☉ |
Luminosity | 95.7+24.6 −19.5[4] L☉ |
Surface gravity (log g) | 4.0[2][4] cgs |
Temperature | 8,974+230 −224[4] K |
Rotational velocity (v sin i) | 183[4] km/s |
Age | 162[2] Myr |
Other designations | |
Database references | |
SIMBAD | data |
The brighter member of the system, designated component A, is an A-type main-sequence star with a stellar classification of A2 V.[2] It is around 162[2] million years old with a high rate of spin, showing a projected rotational velocity of 183 km/s.[4] Estimates of the mass of the star range from 1.7[10] up to 2.73[4] times the mass of the Sun. It is radiating 96[4] times the Sun's luminosity from its photosphere at an effective temperature of 8,974 K.[4]