Kappa1 Apodis

Kappa1 Apodis
Diagram showing star positions and boundaries of the Apus constellation and its surroundings
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 γ Cas[4]
Astrometry
Radial velocity (Rv)+62[5] 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
Distanceapprox. 1,200 ly
(approx. 380 pc)
Absolute magnitude (MV)−2.47[6]
Details
Mass12.0 ± 0.3[7] M☉
Luminosity2,120[6] L☉
Surface gravity (log g)3.90[8] cgs
Temperature21,500[8] K
Age5.6 ± 1.0[7] Myr
Other designations
κ1 Aps, CD−72° 1139, CPD−72° 1802, FK5 567, HD 137387, HIP 76013, HR 5730, SAO 257289[9]
Database references
SIMBADdata

Kappa1 Apodis, Latinized from κ1 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. It is moving away from the Sun with a radial velocity of +62 km/s.[5]

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.[7] 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

  1. 1 2 3 4 5 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. 1 2 3 4 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. 1 2 3 4 5 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. ↑ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/gcvs. 1: 02025. Bibcode:2009yCat....102025S.
  5. 1 2 Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, eds., The Revision of the General Catalogue of Radial Velocities, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E.
  6. 1 2 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.
  7. 1 2 3 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.
  8. 1 2 Soubiran, C.; Le Campion, J.-F.; Cayrel de Strobel, G.; 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.
  9. ↑ "HR 5730". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-08.
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