Alpha Cancri

α Cancri
α Cancri, circled, is the bottom left star in the "crab".
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cancer
Right ascension 08h 58m 29.2042s
Declination +11° 51 27.649
Apparent magnitude (V) 4.20 to 4.27
Characteristics
Spectral type kA7VmF0/2III/IVSr
U−B color index +0.15
B−V color index +0.14
R−I color index +0.04
Astrometry
Radial velocity (Rv)−12.1±0.8 km/s
Proper motion (μ) RA: 42.181 mas/yr
Dec.: −31.160 mas/yr
Parallax (π)18.3304±0.3216 mas
Distance178 ± 3 ly
(54.6 ± 1.0 pc)
Absolute magnitude (MV)0.46
Details
A
Mass2.10 M
Radius3.655 R
Luminosity49 L
Surface gravity (log g)3.73 cgs
Temperature7,943 K
Rotational velocity (v sin i)75 km/s
B
Mass0.38 M
Other designations
Acubens, Sertan, Sartan, α Cnc, Alpha Cancri, Alpha Cnc, 65 Cancri, 65 Cnc, BD+12 1948, FK5 337, GC 12406, HD 76756, HIP 44066, HR 3572, SAO 98267, PPM 125972, ADS 7115 A, CCDM J08585+1151A
Database references
SIMBADdata
B

Alpha Cancri is a star system in the northern constellation of Cancer. Its name is a Bayer designation that is Latinized from α Cancri, and abbreviated Alpha Cnc or α Cnc. The primary component has the proper name Acubens, pronounced /ˈækjuːbɛnz/. It forms a fourth-magnitude star with an apparent magnitude of 4.20, making it barely visible to the naked eye under good viewing conditions. Based on parallax measurements, it is located at a distance of 178 light-years (55 pc) from the Sun, but is drifting closer with a radial velocity of −12 km/s. Since it is near the ecliptic, it can be occulted by the Moon.