Chi1 Hydrae

For other stars with this Bayer designation, see χ Hydrae
Chi1 Hydrae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Hydra
Right ascension 11h 05m 19.90766s[1]
Declination −27° 17′ 36.9957″[1]
Apparent magnitude (V) 4.94[2]
Characteristics
Spectral type F4 V + F7 V[3]
U−B color index +0.04[2]
B−V color index +0.36[2]
Astrometry
Radial velocity (Rv)+19.1±1.6[4] km/s
Proper motion (μ) RA: −190.728[5] mas/yr
Dec.: −6.273[5] mas/yr
Parallax (π)22.8323 ± 0.1828 mas[5]
Distance143 ± 1 ly
(43.8 ± 0.4 pc)
Absolute magnitude (MV)1.74[6]
Orbit[7]
Period (P)7.5535±0.0064 yr
Semi-major axis (a)0.1388±0.0016″
Eccentricity (e)0.349±0.015
Inclination (i)96.50±0.84°
Longitude of the node (Ω)224.00±0.59°
Periastron epoch (T)1983.455 ± 0.084
Argument of periastron (ω)
(secondary)		343.0±4.3°
Details
χ1 Hya A
Mass1.93[8] M☉
Radius3.19[5] R☉
Luminosity17.798[5] L☉
Temperature6,637[5] K
Metallicity [Fe/H]−0.10[6] dex
Age1.3[6] Gyr
χ1 Hya B
Mass1.93[8] M☉
Other designations
χ1 Hya, CD−26°8338, FK5 419, GJ 3642, HD 96202, HIP 54204, HR 4314, SAO 179514[9]
Database references
SIMBADdata

Chi1 Hydrae (χ1 Hydrae) is a binary star[3] in the equatorial constellation of Hydra. It originally received the Flamsteed designation of 9 Crateris before being placed in the Hydra constellation.[10] Based upon an annual parallax shift of 22.8 mas as seen from Earth, it is located about 143 light years from the Sun. It is visible to the naked eye with a combined apparent visual magnitude of 4.94.[2]

The two components of this system appear to have equal masses of 1.93 times the mass of the Sun.[7] The pair circle each other with an orbital period of 7.55 years with an eccentricity of 0.35.[7]

  1. ^ a b Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ a b c d e f Cite error: The named reference dr2 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Nordstroem2004 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Mason1999 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Jaime2012 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Wagman1987 was invoked but never defined (see the help page).