Nu Tucanae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Tucana |
| Right ascension | 22h 33m 00.06240s |
| Declination | −61° 58′ 55.6390″ |
| Apparent magnitude (V) | 4.75 - 4.93 |
| Characteristics | |
| Spectral type | M4 III |
| U−B color index | +1.73 |
| B−V color index | +1.61 |
| Variable type | Lb: |
| Astrometry | |
| Radial velocity (Rv) | −3.4±0.8 km/s |
| Proper motion (μ) | RA: −3.40 mas/yr Dec.: −0.8 mas/yr |
| Parallax (π) | 11.24±0.23 mas |
| Distance | 290 ± 6 ly (89 ± 2 pc) |
| Absolute magnitude (MV) | +0.16 |
| Details | |
| Radius | 64.37 R☉ |
| Luminosity | 554±41 L☉ |
| Surface gravity (log g) | 0.778 cgs |
| Temperature | 3472±125 K |
| Other designations | |
| ν Tuc, CPD−62°6348, FK5 3803, HD 213442, HIP 111310, HR 8582, SAO 255247 | |
| Database references | |
| SIMBAD | data |
ν Tucanae, Latinized as Nu Tucanae, is a solitary, variable star in the southern constellation of Tucana. This red-hued object is visible to the naked eye as a faint star with an apparent visual magnitude that fluctuates around +4.80. It is located approximately 290 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −3 km/s.
This object is an aging red giant with a stellar classification of M4 III, currently on the asymptotic giant branch. With the supply of hydrogen exhausted at its core, the star has cooled and expanded off the main sequence; at present it has 49 times the Sun's radius. It is classified as a slow irregular variable and its brightness varies from magnitude +4.75 to +4.93. Cyclical periods of 22.3, 24.4, 24.8, 25.1, 25.5, 33.8, 50.6, 80.1, 123.2, and 261.8 days have been reported for its variations. On average, the star is radiating around 400 times the luminosity of the Sun from its photosphere at an effective temperature of 3,674 K.