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
Declination −39° 42′ 36.9524″
Apparent magnitude (V) 5.37 (5.37 + 10.90)
Characteristics
Spectral type A0p Si
B−V color index −0.11
Astrometry
Radial velocity (Rv)−7.6±2.8 km/s
Proper motion (μ) RA: −26.10 mas/yr
Dec.: −54.77 mas/yr
Parallax (π)8.02±0.62 mas
Distance410 ± 30 ly
(125 ± 10 pc)
Absolute magnitude (MV)−0.10
Details
υ Lup A
Luminosity113 L☉
Temperature10,049 K
Rotational velocity (v sin i)0 km/s
Other designations
υ Lup, CD−39°9827, HD 136933, HIP 75439, HR 5719, SAO 206597
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. Based upon an annual parallax shift of 8.02 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. As of 1945, the pair had an angular separation of 1.50 arc seconds along a position angle of 40°.

The brighter member, component A, is a chemically peculiar Ap star with a stellar classification of A0p Si, 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. The star is radiating 113 times the solar luminosity from its outer atmosphere at an effective temperature of 10,049 K.

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

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. 1 2 3 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa, 27: 11, Bibcode:1968MNSSA..27...11C.
  3. 1 2 3 Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
  4. 1 2 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
  5. ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  6. ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  7. 1 2 3 McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  8. ↑ Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory, University of Kyoto, Bibcode:1970crvs.book.....U.
  9. ↑ "ups Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-10.
  10. ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  11. ↑ Bychkov, V. D.; et al. (April 2009), "Catalogue of averaged stellar effective magnetic fields - II. Re-discussion of chemically peculiar A and B stars", Monthly Notices of the Royal Astronomical Society, 394 (3): 1338–1350, Bibcode:2009MNRAS.394.1338B, doi:10.1111/j.1365-2966.2008.14227.x, S2CID 120268049.
  12. ↑ Schröder, C.; Schmitt, J. H. M. M. (November 2007), "X-ray emission from A-type stars", Astronomy and Astrophysics, 475 (2): 677–684, Bibcode:2007A&A...475..677S, doi:10.1051/0004-6361:20077429.