Nu Pavonis
Variable star in the constellation Pavo
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Nu Pavonis is a possible triple star system[11] 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.[2] The system lies approximately 440 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +17 km/s.[6] It is a possible member of the Wolf 630 group of co-moving stars.[3]
  | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Pavo |
| Right ascension | 18h 31m 22.42509s[1] |
| Declination | −62° 16′ 41.8853″[1] |
| Apparent magnitude (V) | 4.64 (4.60 - 4.64[2]) |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B7III[4] |
| U−B color index | −0.39[5] |
| B−V color index | −0.11[5] |
| Variable type | SPB[2] |
| Astrometry | |
| Radial velocity (Rv) | +16.95[6] km/s |
| Proper motion (μ) | RA: −1.11[1] mas/yr Dec.: −45.31[1] mas/yr |
| Parallax (π) | 7.43±0.24 mas[1] |
| Distance | 440 ± 10 ly (135 ± 4 pc) |
| Absolute magnitude (MV) | -1.01[4] |
| Orbit[7] | |
| 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[8] M☉ |
| Luminosity | 659[8] L☉ |
| Temperature | 12,764[8] K |
| Rotational velocity (v sin i) | 125.0[9] km/s |
| Other designations | |
| ν Pav, CD−62°1213, GC 25227, HD 169978, HIP 90797, HR 6916, SAO 254273, WDS J18314-6217AB[10] | |
| 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.[7] The unresolved[3] components are close enough that their tidal interaction is significant.[7] Nu Pavonis was discovered to be a variable star when the Hipparcos data was analyzed.[13] The visible component is a slowly pulsating B-type star with a stellar classification of B7III.[4] 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.[3]
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.[8] It too is an X-ray source.[3]