Astronomy:Kappa1 Apodis

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Short description: Star in the constellation Apus


Kappa1 Apodis
Apus constellation map.svg
Red circle.svg
Location of Kappa1 Apodis (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Apus
Right ascension  15h 31m 30.82213s[1]
Declination −73° 23′ 22.5295″[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: +0.996[1] mas/yr
Dec.: −18.345[1] mas/yr
Parallax (π)3.0798 ± 0.0717[1] mas
Distance1,060 ± 20 ly
(325 ± 8 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 1,060 light-years (325 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]

A light curve for Kappa1 Apodis, plotted from TESS data[10]

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.

See also

  • Kappa² Apodis

References

  1. 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement 15: 459, doi:10.1086/190168, Bibcode1968ApJS...15..459G. 
  3. 3.0 3.1 3.2 3.3 3.4 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, doi:10.1088/0004-637X/721/1/469, Bibcode2010ApJ...721..469J. 
  4. Samus, N. N. et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)", VizieR On-line Data Catalog: B/gcvs 1: 02025, Bibcode2009yCat....102025S. 
  5. 5.0 5.1 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, 30, University of Toronto: International Astronomical Union, p. 57, Bibcode1967IAUS...30...57E. 
  6. 6.0 6.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 7.2 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, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode2011MNRAS.410..190T. 
  8. 8.0 8.1 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, doi:10.1051/0004-6361/201014247, Bibcode2010A&A...515A.111S. 
  9. "HR 5730". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HR+5730. 
  10. MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html, retrieved 8 December 2021. 

External links