Kappa1 Apodis

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For other star systems with this Bayer designation, see Kappa Apodis.
Kappa1 Apodis
Diagram showing star positions and boundaries of the Apus constellation and its surroundings
Cercle rouge 100%.svg

Location of κ1 Apodis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Apus
Right ascension 15h 31m 30.82178s[1]
Declination −73° 23′ 22.5291″[1]
Apparent magnitude (V) 5.52[2]
Characteristics
Spectral type B1npe[3]
U−B color index -0.791[2]
B−V color index -0.128[2]
Variable type Be star[3]
Astrometry
Radial velocity (Rv) +62[4] km/s
Proper motion (μ) RA: +0.56[1] mas/yr
Dec.: -18.40[1] mas/yr
Parallax (π) 2.63 ± 0.27[1] mas
Distance approx. 1,200 ly
(approx. 380 pc)
Details
Mass 12.0 ± 0.3[5] M
Surface gravity (log g) 3.90[6] cgs
Temperature 21,500[6] K
Age 5.6 ± 1.0[5] Myr
Other designations
CP-72 1802, FK5 567, HD 137387, HIP 76013, HR 5730, SAO 257289.[7]

Kappa1 Apodis is the Bayer designation for a binary star[3] system in the southern circumpolar constellation of Apus. Based upon parallax measurements, it is located roughly 1,200 light-years (370 parsecs) from Earth. The combined apparent visual magnitude of the system is 5.52,[2] indicating that this is a faint, naked eye star that can be viewed in dark suburban skies.

This is a spectroscopic binary system with an orbital period of 0.6 days.[3] The combined spectrum matches a stellar classification of B1npe.[3] The 'e' suffix indicates that this is a Be star with emission lines in the spectrum. An 'n' means that the absorption lines in the spectrum are broadened from the Doppler effect as a result of rapid rotation. Finally, the 'p' shows some peculiarity in the spectrum. It is classified as a Gamma Cassiopeiae type variable star and its brightness varies from magnitude +5.43 to +5.61.

This is a runaway star with a peculiar velocity of 69.8 ± 4.7 km/s.[5] Because it is a binary star system, it was most likely not turned into a runaway system as the result of a supernova explosion.[3] A companion star is a 12th magnitude orange K-type subgiant located at an angular separation of 27 arcseconds.

References[edit]

  1. ^ a b c d e 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. ^ a b c d Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168. 
  3. ^ a b c d e f Jilinski, E. et al. (September 2010), "A Dynamical Study of Suspected Runaway Stars as Traces of Past Supernova Explosions in the Region of the Scorpius-Centaurus OB Association", The Astrophysical Journal 721 (1): 469–477, Bibcode:2010ApJ...721..469J, doi:10.1088/0004-637X/721/1/469. 
  4. ^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E. 
  5. ^ a b c Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x. 
  6. ^ a b Caillo, A. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247. 
  7. ^ "HR 5730 -- Be Star", SIMBAD Astronomical Object Database (Centre de Données astronomiques de Strasbourg), retrieved 2012-07-08. 

External links[edit]