Upsilon Lupi

Upsilon Lupi
The location of Upsilon Lupi (υ) in the constellation of Lupus (shown as a red target's bullseye).
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lupus
Right ascension 15h 24m 45.00855s[1]
Declination −39° 42′ 36.9524″[1]
Apparent magnitude (V) 5.37[2] (5.37 + 10.90)[3]
Characteristics
Spectral type A0p Si[4]
B−V color index −0.11[2]
Astrometry
Radial velocity (Rv)−7.6±2.8[5] km/s
Proper motion (μ) RA: −26.10[1] mas/yr
Dec.: −54.77[1] mas/yr
Parallax (π)8.02 ± 0.62 mas[1]
Distance410 ± 30 ly
(125 ± 10 pc)
Absolute magnitude (MV)−0.10[6]
Details
υ Lup A
Luminosity113[7] L☉
Temperature10,049[7] K
Rotational velocity (v sin i)0[8] km/s
Other designations
υ Lup, CD−39° 9827, HD 136933, HIP 75439, HR 5719, SAO 206597.[9]
Database references
SIMBADdata

Upsilon Lupi, Latinized from υ Lupi, is a star system in the southern constellation of Lupus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.37.[2] Based upon an annual parallax shift of 8.02[1] mas as seen from Earth, it is located around 410 light years from the Sun. The two components of Upsilon Lupi share a common proper motion through space and most likely form a wide binary star system.[10] As of 1945, the pair had an angular separation of 1.50 arc seconds along a position angle of 40°.[3]

The brighter member, component A, is a chemically peculiar Ap star with a stellar classification of A0p Si,[4] where the 'Si' suffix indicates an abnormal abundance of silicon in the star's photosphere. A magnetic field has been detected with a quadratic field strength of (764.7±311.3)×10−4 T.[11] The star is radiating 113 times the solar luminosity from its outer atmosphere at an effective temperature of 10,049 K.[7]

The magnitude 10.9 companion star, component B, has a visual magnitude of 10.90.[3] It may be the source of the X-ray emission detected coming from these coordinates.[12]

  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 Cite error: The named reference Corben1968 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Mason2014 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference houk1979 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference uesugi_fukuda70 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Bychkova2009 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Schroeder2007 was invoked but never defined (see the help page).