ν Pavonis, Latinized as 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]

Nu Pavonis

Location of ν Pavonis (circled)
Observation data Epoch J2000      Equinox J2000
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] 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]

References