Omega2 Cancri

ω² Cancri is a star in the zodiac constellation Cancer. It has the Flamsteed designation 4 Cancri; ω² Cancri is the Bayer designation, which is Latinised to omega² Cancri and abbreviated to ω² Cnc or omega² Cnc. The star is near the lower limit of visibility to the naked eye, having an apparent visual magnitude of 6.32.^[1] Based on parallax measurements, it is located around 432 light-years (133 pc) away from the Sun. It is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.^[5] The position of this star near the ecliptic means it is subject to lunar occultations.^[7]

For other star systems with this Bayer designation, see ω Cancri.

ω² Cancri

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cancer[1]
Right ascension	08h 01m 43.757s[2]
Declination	+25° 05′ 22.08″[2]
Apparent magnitude (V)	6.32[1]
Characteristics
Evolutionary stage	main sequence[3]
Spectral type	A1 V[4]
B−V color index	0.023±0.006[1]
Astrometry
Radial velocity (Rv)	−7.6±2.5[5] km/s
Proper motion (μ)	RA: −25.138 mas/yr[2] Dec.: +12.276 mas/yr[2]
Parallax (π)	7.5434±0.0393 mas[2]
Distance	432 ± 2 ly (132.6 ± 0.7 pc)
Absolute magnitude (MV)	0.51[1]
Details
Mass	2.59±0.06[3] M☉
Radius	2.55±0.02[2] R☉
Luminosity	68.0+8.3 −7.3[3] L☉
Surface gravity (log g)	3.886±0.006[2] cgs
Temperature	9,354+174 −171[3] K
Rotational velocity (v sin i)	159[3] km/s
Age	506±75[2] Myr
Other designations
ω2 Cancri, 4 Cnc, BD+25°1816, HD 65856, HIP 39263, HR 3132, SAO 79869, CCDM J08017+2506A, WDS J08017+2505A, GSC 01930-00674[6]
Database references
SIMBAD	data

This is an ordinary A-type main-sequence star with a stellar classification of A1 V,^[4] which indicates it is generating energy through hydrogen fusion at its core. At an estimated age of approximately 500^[2] million years, it is spinning rapidly with a projected rotational velocity of 159 km/s.^[3] It has 2.6^[3] times the mass of the Sun and about 2.55 times the Sun's radius.^[2] The star is radiating 68^[3] times the Sun's luminosity from its photosphere at an effective temperature of 9,354 K.^[3]