Nu Octantis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Octans |
| Right ascension | 21h 41m 28.64977s |
| Declination | −77° 23′ 24.1563″ |
| Apparent magnitude (V) | 3.73 |
| Characteristics | |
| A | |
| Evolutionary stage | Subgiant |
| Spectral type | K1IV |
| U−B color index | +0.89 |
| B−V color index | +1.00 |
| B | |
| Evolutionary stage | white dwarf |
| Astrometry | |
| Radial velocity (Rv) | +34.40 km/s |
| Proper motion (μ) | RA: +66.41 mas/yr Dec.: −239.10 mas/yr |
| Parallax (π) | 45.25±0.25 mas |
| Distance | 73.5±0.68 ly (22.54±0.21 pc) |
| Absolute magnitude (MV) | 2.3±0.16 |
| Orbit | |
| Period (P) | 1050.74+0.20 −0.10 days |
| Semi-major axis (a) | 2.61±0.03 AU |
| Eccentricity (e) | 0.2366±0.0003 |
| Inclination (i) | 71.8+0.7 −0.6° |
| Longitude of the node (Ω) | 86.5±0.3° |
| Argument of periastron (ω) (secondary) | 74.88+0.06 −0.14° |
| Semi-amplitude (K2) (secondary) | 7.0648+0.0050 −0.0009 km/s |
| Details | |
| Nu Octantis A | |
| Mass | 1.57±0.06 M☉ |
| Radius | 5.04±0.10 R☉ |
| Luminosity | 13.2±0.3 L☉ |
| Surface gravity (log g) | 3.23+0.02 −0.03 cgs |
| Temperature | 4,910+21 −30 K |
| Metallicity [Fe/H] | +0.18±0.04 dex |
| Rotational velocity (v sin i) | 2.0 km/s |
| Age | 2.70±0.35 Gyr |
| Nu Octantis B | |
| Mass | 0.57±0.01 M☉ |
| Other designations | |
| nu Oct, CD−77 1079, CCDM J21415-7723, FK5 810, GC 30289, GJ 835.1, GJ 9744, HIP 107089, HR 8254, HD 205478, SAO 257948, WDS J21415-7723 | |
| Database references | |
| SIMBAD | data |
ν Octantis, Latinised as Nu Octantis, is a binary star in the constellation of Octans. Unusually for having such a late greek letter in its name, it is the brightest star in this faint constellation at apparent magnitude +3.7. It is located at 22.54 parsecs (73.5 light-years) from Earth, and is moving away at a radial velocity of +34.4 km/s. The system has an exoplanet orbiting halfway between both stars.