Kappa2 Apodis

Kappa2 Apodis (κ2 Apodis) is the Bayer designation for a double star in the southern circumpolar constellation of Apus. It is located at a distance of roughly 780 light-years (240 parsecs) from Earth, based upon parallax measurements with a 7% margin of error. The pair have a combined apparent visual magnitude of +5.65,[2] which makes the system faintly visible to the naked eye.

For other star systems with this Bayer designation, see Kappa Apodis.
Kappa2 Apodis
Location of κ2 Apodis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Apus
Right ascension  15h 40m 21.33360s[1]
Declination –73° 26′ 48.0648″[1]
Apparent magnitude (V) 5.65[2]
Characteristics
Spectral type B7 III-IV + K0 V[3]
U−B color index –0.38[2]
B−V color index –0.04[2]
Astrometry
Radial velocity (Rv)–19.0[4] km/s
Proper motion (μ) RA: –12.36[1] mas/yr
Dec.: –20.56[1] mas/yr
Parallax (π)4.18 ± 0.28[1] mas
Distance780 ± 50 ly
(240 ± 20 pc)
Absolute magnitude (MV)−1.24[5]
Details
Luminosity351[5] L☉
Other designations
CPD–73° 1625, HD 138800, HIP 76750, HR 5782, SAO 257307.[6]
Database references
SIMBADdata

The brighter star has a stellar classification of B7 III-IV, with the luminosity class of III-IV suggesting that it may lie in an intermediate stage between a subgiant and a giant star.[7] The faint companion is a K-type main sequence star with a classification of K0 V. It has a visual magnitude of 12.5 and an angular separation of 15 arcseconds from the brighter member.[3]

References
  1. van Leeuwen, F. (November 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.
  2. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.
  3. 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.
  4. Wilson, Ralph Elmer (1953), General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
  5. 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.
  6. "HR 5782 -- Star in double system", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-10.
  7. Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1975mcts.book.....H.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.