Astronomy:Kappa2 Apodis

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Short description: Double star in the constellation Apus


κ2 Apodis
Apus constellation map.svg
Red circle.svg
Location of κ2 Apodis (circled)
Observation data
Equinox J2000.0]] (ICRS)
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

Kappa2 Apodis2 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.

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]

See also

References

  1. 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. 3.0 3.1 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  4. Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication (Washington: Carnegie Institution of Washington), Bibcode1953GCRV..C......0W. 
  5. 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  6. "HR 5782 -- Star in double system", SIMBAD Astronomical Object Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+138800, 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, Bibcode1975mcts.book.....H. 

External links