Kappa Tucanae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Tucana |
| κ Tuc AB | |
| Right ascension | 01h 15m 46.0891s (A) 01h 15m 46.5740s (B) |
| Declination | −68° 52′ 33.401″ (A) −68° 52′ 33.516″ (B) |
| Apparent magnitude (V) | 4.88 + 7.54 |
| κ Tuc C | |
| Right ascension | 01h 15m 01.0248s |
| Declination | −68° 49′ 08.374″ |
| Apparent magnitude (V) | 7.76 |
| κ Tuc D | |
| Right ascension | 01h 15m 00.7519s |
| Declination | −68° 49′ 07.791″ |
| Apparent magnitude (V) | 8.26 |
| Characteristics | |
| Evolutionary stage | Subgiant (Aa) Main sequence (others) |
| Spectral type | F6IV (Aa) M3.5V/M4.5V (Ab) G5V (B) K2V (C) K3V (D) |
| B−V color index | 0.48 |
| Astrometry | |
| AB | |
| Radial velocity (Rv) | +7.7±1.7 km/s |
| Proper motion (μ) | RA: +386.257 mas/yr Dec.: +82.069 mas/yr |
| Parallax (π) | 47.6500±0.0203 mas |
| Distance | 68.45 ± 0.03 ly (20.986 ± 0.009 pc) |
| Absolute magnitude (MV) | 3.50 |
| Orbit | |
| Primary | κ Tuc Aa |
| Name | κ Tuc Ab |
| Period (P) | 8.14+0.11 −0.10 years |
| Semi-major axis (a) | 4.822+0.077 −0.071 AU |
| Eccentricity (e) | 0.9356±0.0024 |
| Inclination (i) | 126.13±0.80° |
| Longitude of the node (Ω) | 189.0+1.1 −1.0° |
| Periastron epoch (T) | 60,219.8±1.8 MJD |
| Argument of periastron (ω) (secondary) | 180.0+1.5 −1.4° |
| Semi-amplitude (K1) (primary) | 8 km/s |
| Orbit | |
| Primary | κ Tuc A |
| Name | κ Tuc B |
| Period (P) | 1,122±28 years |
| Semi-major axis (a) | 7.03±0.07″ |
| Eccentricity (e) | 0.40 |
| Inclination (i) | 128.5±1.1° |
| Longitude of the node (Ω) | 323.1±0.5° |
| Periastron epoch (T) | 2086.7±4.1 |
| Argument of periastron (ω) (secondary) | 61.3±1.6° |
| Orbit | |
| Primary | κ Tuc C |
| Name | κ Tuc D |
| Period (P) | 85.12±0.11 years |
| Semi-major axis (a) | 1.094±0.007″ |
| Eccentricity (e) | 0.039±0.002 |
| Inclination (i) | 31.3±0.5° |
| Longitude of the node (Ω) | 141.0±0.9° |
| Periastron epoch (T) | 1916.92±1.20 |
| Argument of periastron (ω) (secondary) | 135.7±4.6° |
| Details | |
| κ Tuc Aa | |
| Mass | 1.37+0.06 −0.04 M☉ |
| Radius | 1.71±0.05 R☉ |
| Luminosity | 4.59±0.31 L☉ |
| Temperature | 6,457+57 −66 K |
| Rotational velocity (v sin i) | 61.1±3.1 km/s |
| Age | 2.28+0.43 −0.42 Gyr |
| κ Tuc Ab | |
| Mass | 0.33±0.10 M☉ |
| Age | ~2 Gyr |
| κ Tuc B | |
| Mass | 0.88 M☉ |
| Radius | 0.831±0.050 R☉ |
| Luminosity | 0.421±0.010 L☉ |
| Surface gravity (log g) | 4.53±0.08 cgs |
| Temperature | 5,145 K |
| Age | ~2 Gyr |
| κ Tuc C | |
| Mass | 0.86 M☉ |
| Radius | 0.93±0.07 R☉ |
| Luminosity | 0.387±0.009 L☉ |
| Temperature | 5,062 K |
| Age | ~2 Gyr |
| κ Tuc D | |
| Mass | 0.80 M☉ |
| Radius | 0.71±0.05 R☉ |
| Luminosity | 0.239±0.007 L☉ |
| Temperature | 4,850 K |
| Age | ~2 Gyr |
| Other designations | |
| κ Tuc, WDS J01158-6853 | |
| AB: CD−69°52, GJ 55.3, GJ 9049, HD 7788, HIP 5896, HR 377, SAO 248346 | |
| CD: CD−69°51, GJ 55.1, HD 7693, HIP 5842, SAO 248342 | |
| Database references | |
| SIMBAD | A |
| B | |
| CD | |
| C | |
| D | |
Kappa Tucanae, Latinised from κ Tucanae, is a quintuple star system in the southern constellation Tucana. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of +4.86. The system is located approximately 68 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +8 km/s.
Temporally variable excess emission, likely originating from hot exozodiacal dust, has been detected around Kappa Tucanae A.