Tau2 Lupi

For other stars with this Bayer designation, see τ Lupi.
Tau2 Lupi
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lupus
Right ascension 14h 26m 10.81378s[1]
Declination −45° 22′ 45.4023″[1]
Apparent magnitude (V) 4.34[2] (4.93 + 5.55)[3]
Characteristics
Spectral type F4 IV + A7:[3]
U−B color index +0.16[2]
B−V color index +0.43[2]
Astrometry
Radial velocity (Rv)−0.60±1.60[4] km/s
Proper motion (μ) RA: +14.62[1] mas/yr
Dec.: −7.33[1] mas/yr
Parallax (π)10.22 ± 0.31 mas[1]
Distance319 ± 10 ly
(98 ± 3 pc)
Absolute magnitude (MV)−0.62[5]
Orbit[6]
Period (P)26.2 yr
Semi-major axis (a)0.125″
Eccentricity (e)0.94
Inclination (i)56.0°
Longitude of the node (Ω)175.7°
Periastron epoch (T)1969.1
Argument of periastron (ω)
(secondary)		191.0°
Details
Luminosity150[5] L☉
Rotational velocity (v sin i)0[7] km/s
Other designations
τ2 Lup, CD−44° 9323, HD 126354, HIP 70576, HR 5396, SAO 224920.[8]
Database references
SIMBADdata

Tau2 Lupi, Latinized from τ2 Lup, is a binary star[3] system in the constellation Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.34.[2] Based upon an annual parallax shift of 10.22[1] mas as seen from Earth, it is located around 319 light years from the Sun. The two components orbit each other with a period of 26.2 years and a high eccentricity of 0.94.[6] The brighter component is a magnitude 4.93 subgiant star with a stellar classification of F4 IV. Its companion is an A-type star with visual magnitude 5.55 and class A7:.[3]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Heintz1986 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Uesugi1970 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).