KU Hydrae

A visual band light curve for KU Hydrae, adapted from Adelman (2006)[1]
Observation data
Epoch J2000      Equinox J2000
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 mas[3]
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, A 1342[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. Bibcode:2006PASP..118...77A. doi:10.1086/498223.
  2. ^ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Vizier query form
  3. ^ a b c d e van Leeuwen, F. (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. S2CID 18759600.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. ^ a b "V* KU Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2014-09-01.
  6. ^ a b 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) 50. arXiv:1506.05718. Bibcode:2015AJ....150...50T. doi:10.1088/0004-6256/150/2/50.
  8. ^ a b Rica Romero, F. M. (2010). "Orbital elements for eight binaries. Study of the nature of wide components. I" (PDF). Revista Mexicana de Astronomía y Astrofísica. 46: 263–277. Bibcode:2010RMxAA..46..263R.
  9. ^ Aitken, Robert Grant (1907). "Two hundred and fifty new double stars: tenth list". Lick Observatory Bulletin. 4 (109): 101–106. Bibcode:1907LicOB...4..101A. doi:10.5479/ADS/bib/1907LicOB.4.101A.
  10. ^ Aitken, Robert Grant (1929). "Measures of 296 A double stars". Lick Observatory Bulletin. 14 (413): 62–87. Bibcode:1929LicOB..14...62A. doi:10.5479/ADS/bib/1929LicOB.14.62A.


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