Astronomy:KU Hydrae

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Short description: Star in the constellation Hydra
KU Hydrae
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A visual band light curve for KU Hydrae, adapted from Adelman (2006)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Hydra[2]
Right ascension  09h 22m 50.856s[3]
Declination −09° 50′ 19.66″[3]
Apparent magnitude (V) 6.75[4]
Characteristics
Spectral type Ap EuCrSr[5]
U−B color index +0.11[6]
B−V color index +0.22[6]
Variable type α2 CVn
Astrometry
Radial velocity (Rv)19.6 ± 5.0 km/s
Proper motion (μ) RA: −27.94 ± 0.61[3] mas/yr
Dec.: −13.01 ± 0.36[3] mas/yr
Parallax (π)6.92 ± 0.61[3] mas
Distance470 ± 40 ly
(140 ± 10 pc)
Orbit[7]
CompanionKU Hya B
Period (P)52.98(37) yr
Semi-major axis (a)0.169(1)″
Eccentricity (e)0.074(8)
Inclination (i)68.5(6)°
Longitude of the node (Ω)202.4(4)°
Periastron epoch (T)2020.20(45)
Argument of periastron (ω)
(secondary)
58.7(3.3)°
Details[8]
KU Hya A
Mass2.07 M☉
KU Hya B
Mass2.05 M☉
Other designations
BD−09° 2816, HD 81009, HIP 45999, HR 3724, SAO 136799[5]
Database references
SIMBADdata

KU Hydrae is a binary star in the constellation Hydra. The primary star is an Alpha2 Canum Venaticorum variable with its apparent magnitude varying from 0.05 magnitudes over a period of 33.97 days.[8]

This star was discovered to be a visual binary star by Robert Grant Aitken in 1906 and was given the double star designation A 1342.[9] Additional measurements of the position angle and angular separation showed a rapid orbital motion.[10]

References

  1. ↑ Adelman, Saul J. (January 2006). "FCAPT uvby Photometry of the mCP Stars HD 20629, HR 3724, 45 Leo, and HD 192678". Publications of the Astronomical Society of the Pacific 118 (839): 77–83. doi:10.1086/498223. Bibcode: 2006PASP..118...77A. 
  2. ↑ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific 99 (617): 695–699. doi:10.1086/132034. Bibcode: 1987PASP...99..695R.  Vizier query form
  3. ↑ 3.0 3.1 3.2 3.3 3.4 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. Vizier catalog entry
  4. ↑ Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode: 2002yCat.2237....0D. 
  5. ↑ 5.0 5.1 "V* KU Hya". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V%2A+KU+Hya. 
  6. ↑ 6.0 6.1 Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99. Bibcode: 1966CoLPL...4...99J. 
  7. ↑ Tokovinin, Andrei et al. (2015-07-17). "Speckle Interferometry at SOAR in 2014". The Astronomical Journal 150 (2). doi:10.1088/0004-6256/150/2/50. Bibcode: 2015AJ....150...50T. 
  8. ↑ 8.0 8.1 Rica Romero, F. M. (2010). "Orbital elements for eight binaries. Study of the nature of wide components. I". Revista Mexicana de Astronomía y Astrofísica 46: 263–277. Bibcode: 2010RMxAA..46..263R. http://www.astroscu.unam.mx/rmaa/RMxAA..46-2/PDF/RMxAA..46-2_frica.pdf. Retrieved 2014-09-01. 
  9. ↑ Aitken, Robert Grant (1907). "Two hundred and fifty new double stars: tenth list". Lick Observatory Bulletin 4 (109): 101–106. doi:10.5479/ADS/bib/1907LicOB.4.101A. Bibcode: 1907LicOB...4..101A. 
  10. ↑ Aitken, Robert Grant (1929). "Measures of 296 A double stars". Lick Observatory Bulletin 14 (413): 62–87. doi:10.5479/ADS/bib/1929LicOB.14.62A. Bibcode: 1929LicOB..14...62A.