Nu Pavonis
𝜈 Pavonis, Latinized as Nu Pavonis, is a possible triple star system in the southern constellation of Pavo. It is visible to the naked eye as a faint star that varies in apparent visual magnitude from 4.60 to 4.64 over a period of 0.85584 days. The system lies approximately 440 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +17 km/s. It is a possible member of the Wolf 630 group of co-moving stars.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pavo |
| Right ascension | 18h 31m 22.42509s |
| Declination | −62° 16′ 41.8853″ |
| Apparent magnitude (V) | 4.64 (4.60 - 4.64) |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | B7III |
| U−B color index | −0.39 |
| B−V color index | −0.11 |
| Variable type | SPB |
| Astrometry | |
| Radial velocity (Rv) | +16.95 km/s |
| Proper motion (μ) | RA: −1.11 mas/yr Dec.: −45.31 mas/yr |
| Parallax (π) | 7.43 ± 0.24 mas |
| Distance | 440 ± 10 ly (135 ± 4 pc) |
| Absolute magnitude (MV) | -1.01 |
| Orbit | |
| Period (P) | 1.711529±0.000005 d |
| Eccentricity (e) | 0.0 |
| Periastron epoch (T) | 2,450,276.5502±0.0007 HJD |
| Argument of periastron (ω) (secondary) | 127±12° |
| Semi-amplitude (K1) (primary) | 43.8±0.1 km/s |
| Details | |
| Mass | 4.39 M☉ |
| Luminosity | 659 L☉ |
| Temperature | 12,764 K |
| Rotational velocity (v sin i) | 125.0 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a single-lined spectroscopic binary system with an orbital period of just 1.71 days in a circular orbit. The unresolved components are close enough that their tidal interaction is significant. The visible component is a slowly pulsating B-type star with a stellar classification of B7III. This implies it is an evolved giant star, but it is actually more likely to be on the main sequence. An X-ray emission has been detected from the pair.
The third component is a visible companion, probably a pre-main-sequence star, at magnitude 13.7 and separation 3.1″. This star is estimated at 0.15 solar masses and an effective temperature of 3,192 K. It too is an X-ray source.