Nu Pictoris

ν Pictoris
Location of ν Pictoris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Pictor
Right ascension 06h 22m 55.82671s[1]
Declination −56° 22′ 11.8909″[1]
Apparent magnitude (V) 5.60[2]
Characteristics
Spectral type A1mA3-A9[3]
U−B color index 0.12[4]
B−V color index 0.26[4]
Astrometry
Radial velocity (Rv)+6.7±2.9[2] km/s
Proper motion (μ) RA: −39.96[1] mas/yr
Dec.: −20.13[1] mas/yr
Parallax (π)20.72 ± 0.56 mas[1]
Distance157 ± 4 ly
(48 ± 1 pc)
Absolute magnitude (MV)+2.18[2]
Orbit[5]
Period (P)452+13
−16 d
Semi-major axis (a)5.9+1.6
−0.9 mas
Eccentricity (e)0.20+0.35
−0.19
Inclination (i)116+12
−10°
Longitude of the node (Ω)53+166
−16°
Periastron epoch (T)2448660
Argument of periastron (ω)
(secondary)		109±53°
Details
Radius2.19+0.12
−0.10[6] R☉
Luminosity15.4±0.4[6] L☉
Temperature7,733+170
−203[6] K
Other designations
ν Pic, CPD−56°1072, GC 8274, HD 45229, HIP 30342, HR 2320, SAO 234473, TYC 8542-1469-1[7]
Database references
SIMBADdata

ν Pictoris, Latinized as Nu Pictoris, is a binary star system in the southern Pictor constellation. It is visible to the naked eye as a dim point of light with an apparent visual magnitude of 5.60.[2] The system is located around 157 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +7 km/s.[2]

Hipparcos satellite astrometry showed that ν Pictoris moved in a way that was not consistent with the proper motion and annual parallax of a single star. The unusual measurements were not readily identifiable as being due to orbital motion, and it was referred to as having a stochastic solution to its astrometry. Later analysis derived an orbit, although nothing is known about the companion except its approximate mass and motion about the visible star.[5]

The pair orbit each other with a period of 452 days and an eccentricity of 0.2.[5] The primary, component A, is a metal-lined Am star with a stellar classification of A1mA3-A9.[3] It has 2.2 times the radius of the Sun and is radiating 15 times the Sun's luminosity from its photosphere at an effective temperature of 7,733 K.[6] The secondary, component B, has around one fourth the mass of the primary.[8][5] The system is a source for X-ray emission, which is most likely coming from the companion.[9]

  1. ^ a b c d e Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference UBV was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Goldin2007 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Goldin2006 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Schröder2007 was invoked but never defined (see the help page).