Kappa Cancri
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| Right ascension | 09h 07m 44.80955s |
| Declination | +10° 40′ 05.5196″ |
| Apparent magnitude (V) | +5.233 |
| Characteristics | |
| Spectral type | B8 IIIp |
| B−V color index | −0.113 |
| Variable type | α2 CVn |
| Astrometry | |
| Proper motion (μ) | RA: −18.31 mas/yr Dec.: −12.105 mas/yr |
| Parallax (π) | 5.3209±0.1298 mas |
| Distance | 610 ± 10 ly (188 ± 5 pc) |
| Absolute magnitude (MV) | −0.82 |
| Orbit | |
| Period (P) | 6.3933 d |
| Eccentricity (e) | 0.13 |
| Periastron epoch (T) | 2440001.95 JD |
| Argument of periastron (ω) (secondary) | 157° |
| Semi-amplitude (K1) (primary) | 67.4 km/s |
| Details | |
| κ Cnc A | |
| Mass | 4.5 M☉ |
| Radius | 5.0 R☉ |
| Luminosity | 322 L☉ |
| Surface gravity (log g) | 3.7±0.1 cgs |
| Temperature | 12,800±200 K |
| Metallicity [Fe/H] | +0.51 dex |
| Rotational velocity (v sin i) | 6±2 km/s |
| κ Cnc B | |
| Mass | 2.1 M☉ |
| Radius | 2.4 R☉ |
| Surface gravity (log g) | 4.0 cgs |
| Temperature | 8,500 K |
| Rotational velocity (v sin i) | 40 km/s |
| Other designations | |
| κ Cnc, 76 Cancri, BD+11°1984, FK5 1238, HD 78316, HIP 44798, HR 3623, SAO 98378 | |
| Database references | |
| SIMBAD | data |
Kappa Cancri, Latinized from κ Cancri, is a blue-white hued binary star system in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.23. The magnitude difference between the two stars is about 2.6. Based upon an annual parallax shift of 5.3209 mas as seen from the Earth, the system is located roughly 610 light-years from the Sun. The position of this system near the ecliptic means it is subject to lunar occultation.
This is a single-lined spectroscopic binary star system with an orbital period of 6.39 days and an eccentricity of 0.13. The primary, component A, has a stellar classification of B8 IIIp, suggesting it is a B-type giant star. It a mercury-manganese star, a type of chemically peculiar star showing large overabundances of those two elements in the outer atmosphere. It is classified as an Alpha2 Canum Venaticorum type variable star and its brightness varies from magnitude +5.22 to +5.27 with a period of five days.
The primary component has 4.5 times the mass of the Sun, five times the Sun's radius, and an effective temperature of 13,200 K. The secondary, component B, is a smaller star with 2.1 times the mass and 2.4 times the radius of the Sun, having an effective temperature of 8,500 K.