Astronomy:BX Boötis

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Short description: Star in the constellation Boötes
BX Boötis
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The visual band light curve of BX Boötes, adapted from Adelman (2008)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Boötes
Right ascension  15h 00m 38.7179s[2]
Declination +47° 16′ 38.792″[2]
Apparent magnitude (V) 6.33 to 6.41[3]
Characteristics
Spectral type A0 Vsp SiSrCr[4] or B9 Vp SiCrSr[5]
B−V color index −0.099±0.004[6]
Variable type α2 CVn[7]
Astrometry
Radial velocity (Rv)−10.7±1.8[8] km/s
Proper motion (μ) RA: -8.999[2] mas/yr
Dec.: 15.852[2] mas/yr
Parallax (π)6.3665 ± 0.0287[2] mas
Distance512 ± 2 ly
(157.1 ± 0.7 pc)
Absolute magnitude (MV)0.21[6]
Details
Mass2.70±0.09[9] M☉
Radius2.51[10] R☉
Luminosity72.4+10.8
−12.1[9] L☉
Surface gravity (log g)4.50[11] cgs
Temperature9,164[11] K
Metallicity [Fe/H]+0.63[11] dex
Rotation2.88756 d[1]
Rotational velocity (v sin i)30[12] km/s
Age235[13] Myr
Other designations
BX Boo, BD+47° 2192, FK5 3247, HD 133029, HIP 73454, HR 5597, SAO 45326[14]
Database references
SIMBADdata

BX Boötis is a star in the northern constellation of Boötes. It is a dim star near the lower limit of visibility to the naked eye, having a nominal apparent visual magnitude of 6.35.[10] Based upon an annual parallax shift of 6.3665 mas,[2] it is located 512 light years away. At that distance, the visual magnitude of the star is diminished by an extinction of 0.13 due to interstellar dust.[13] It is moving closer with a heliocentric radial velocity of −11 km/s.[8]

The variability of BX Boötis was probably discovered by Gerhard Robert Miczaika. It was announced in a 1954 IAU publication, where he discusses photo-electric measurements of spectrum variables. He wrote "The magnetic-field variable HD 133129 is likewise variable in magnitude with a small amplitude."[15] HD 133129 is not BX Boötis, but HD 133029 is. Unlike BX Boötis, HD 133129 does not match Miczaika's description of the star. Kukarkin et al. apparently concluded there was a typographical error in Miczaika's announcement, because they cited Miczaika's 1954 announcement when they gave BX Boötis its variable star designation in 1972.[16]

This is a magnetic CP star[1] with a stellar classification of A0 Vsp SiSrCr,[4] indicating this is an A-type main-sequence star. The spectrum has very weak lines of helium but displays strong overabundances of silicon and all of the heavier elements except nickel.[17] It is classified as an Alpha² Canum Venaticorum variable[7] with a magnitude that varies from 6.33 to 6.41[3] over a period of 2.88756 days.[1]

BX Boötis is 235[13] million years old with a projected rotational velocity of 30[12] km/s. It has 2.7[9] times the mass of the Sun and 2.5[10] times the Sun's radius. The star is radiating around 72[9] times the Sun's luminosity from its photosphere at an effective temperature of 9,164 K.[11]

References

  1. ↑ 1.0 1.1 1.2 1.3 Adelman, Saul J. (June 2008), "FCAPT uvby Photometry of the mCP Stars HR 1297, 25 Sex, BX Boo, and 49 Her", Publications of the Astronomical Society of the Pacific 120 (868): 595–601, doi:10.1086/588680, Bibcode: 2008PASP..120..595A. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. 
  3. ↑ 3.0 3.1 Watson, Christopher (January 4, 2010), "BX Boötis", AAVSO Website (American Association of Variable Star Observers), http://www.aavso.org/vsx/index.php?view=detail.top&oid=4404, retrieved 5 August 2014. 
  4. ↑ 4.0 4.1 Abt, H. A.; Cardona, O. (1984), "The nature of the visual companions of AP and AM stars", Astrophysical Journal 276: 266, doi:10.1086/161610, Bibcode: 1984ApJ...276..266A. 
  5. ↑ Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, doi:10.1086/110819, Bibcode: 1969AJ.....74..375C. 
  6. ↑ 6.0 6.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A. 
  7. ↑ 7.0 7.1 Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S. 
  8. ↑ 8.0 8.1 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D. 
  9. ↑ 9.0 9.1 9.2 9.3 Kochukhov, O.; Bagnulo, S. (2006), "Evolutionary state of magnetic chemically peculiar stars", Astronomy and Astrophysics 450 (2): 763, doi:10.1051/0004-6361:20054596, Bibcode: 2006A&A...450..763K. 
  10. ↑ 10.0 10.1 10.2 Shulyak, D. et al. (September 2014), "Interferometry of chemically peculiar stars: theoretical predictions versus modern observing facilities", Monthly Notices of the Royal Astronomical Society 443 (2): 1629–1642, doi:10.1093/mnras/stu1259, Bibcode: 2014MNRAS.443.1629S. 
  11. ↑ 11.0 11.1 11.2 11.3 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, Bibcode: 2010A&A...515A.111S. 
  12. ↑ 12.0 12.1 Strom, Stephen E. et al. (2005), "B Star Rotational Velocities in h and χ Persei: A Probe of Initial Conditions during the Star Formation Epoch?", The Astronomical Journal 129 (2): 809–828, doi:10.1086/426748, Bibcode: 2005AJ....129..809S. 
  13. ↑ 13.0 13.1 13.2 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode: 2012AstL...38..694G. 
  14. ↑ "HD 46052". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+46052. 
  15. ↑ Miczaika, G. R. (September 1954). "Photometric Measurements of Magnetic-Field and Spectrum Variables". Transactions of the International Astronomical Union 8: 805. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/9DABD82D0CDA5A13B8C04D1BB2183F32/S0251107X00032922a.pdf/2_photometric_measurements_of_magneticfield_and_spectrum_variables.pdf. Retrieved 3 December 2024. 
  16. ↑ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (September 1972). "58th Name-List of Variable Stars". Information Bulletin on Variable Stars 717. Bibcode: 1972IBVS..717....1K. https://ibvs.konkoly.hu/pub/ibvs/0701/0717.pdf. Retrieved 2 December 2024. 
  17. ↑ López-García, Z.; Adelman, S. J. (June 1999), "Elemental abundance studies of CP stars. II. The silicon stars HD 133029 and HD 192913", Astronomy and Astrophysics Supplement 137 (2): 227–232, doi:10.1051/aas:1999247, Bibcode: 1999A&AS..137..227L. 



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