Sigma2 Cancri
White-hued subgiant star in the constellation Cancer
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Sigma2 Cancri is a solitary,[8] white-hued star in the constellation Cancer. Its name is a Bayer designation that is Latinized from σ2 Cancri, and abbreviated Sigma2 Cnc σ2 Cnc. This star is faintly visible to the naked eye, having an apparent visual magnitude of +5.44.[3] Based upon an annual parallax shift of 17.04 mas as seen from Earth,[2] this star is located 191 light-years (59 pc) from the Sun. It is drifting closer to the Sun with a radial velocity of −26 km/s.[5]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer[1] |
| Right ascension | 08h 56m 56.598s[2] |
| Declination | +32° 54′ 37.54″[2] |
| Apparent magnitude (V) | +5.436[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4][2] |
| Spectral type | A7 IV[4] |
| B−V color index | +0.157[3] |
| Astrometry | |
| Radial velocity (Rv) | −26.2±0.7[5] km/s |
| Proper motion (μ) | RA: −53.031 mas/yr[2] Dec.: −66.186 mas/yr[2] |
| Parallax (π) | 17.0377±0.0716 mas[2] |
| Distance | 191.4 ± 0.8 ly (58.7 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.57[1] |
| Details | |
| Mass | 1.79[6] M☉ |
| Radius | 2.28+0.02 −0.04[2] R☉ |
| Luminosity | 21.5[4] L☉ |
| Surface gravity (log g) | 4.17[6] cgs |
| Temperature | 8,309±283[6] K |
| Rotational velocity (v sin i) | 133[4] km/s |
| Age | 441[6] Myr |
| Other designations | |
| σ2 Cnc, 59 Cancri, BD+33°1785, HD 76398, HIP 43932, HR 3555, SAO 61146[7] | |
| Database references | |
| SIMBAD | data |
With an estimated age of 441[6] million years, this is an A-type subgiant star with a stellar classification of A7 IV.[4] It is spinning rapidly with a projected rotational velocity of 133 km/s.[4] The star has an estimated 1.8[6] times the mass of the Sun with 2.3 times the Sun's radius.[2] It is radiating 21.5[4] times the Sun's luminosity from its photosphere at an effective temperature of roughly 8,309 K.[6]