KU Hydrae

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]

  1. ^ Cite error: The named reference Adelman was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Roman1987 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  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 Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  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. ^ Cite error: The named reference Tokovinin2015 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Rica Romero2010 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Aitken1907 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Aitken1929 was invoked but never defined (see the help page).