Sigma Hydrae

Sigma Hydrae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Hydra
Right ascension 08h 38m 45.43747s[1]
Declination +03° 20′ 29.1701″[1]
Apparent magnitude (V) 4.48[2]
Characteristics
Spectral type K2 III[3]
U−B color index +1.23[2]
B−V color index +1.21[2]
Astrometry
Radial velocity (Rv)27.28±0.19[4] km/s
Proper motion (μ) RA: −19.48[1] mas/yr
Dec.: −15.92[1] mas/yr
Parallax (π)8.75 ± 0.25 mas[1]
Distance370 ± 10 ly
(114 ± 3 pc)
Absolute magnitude (MV)−0.84[5]
Details[6]
Mass3.07 M☉
Radius27.6[7] R☉
Luminosity295 L☉
Surface gravity (log g)2.21±0.13[8] cgs
Temperature4,491±51 K
Metallicity [Fe/H]0.13±0.06[8] dex
Age430 Myr
Other designations
σ Hya, 5 Hydrae, BD+03°2026, FK5 1224, HD 73471, HIP 42402, HR 3418, SAO 116988.[9]
Database references
SIMBADdata

Sigma Hydrae (σ Hydrae, abbreviated Sigma Hya, σ Hya), also named Minchir /ˈmɪŋkər/,[10] is a solitary[11] star in the equatorial constellation of Hydra. It is visible to the naked eye with an apparent visual magnitude of 4.48.[2] The estimated distance to this star from the Sun, based upon an annual parallax shift of 8.75 mas,[1] is around 370 light-years. At that distance, the visual magnitude of the star is diminished by an interstellar extinction factor of 0.16,[4] due to intervening dust.

  1. ^ a b c d e f 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 Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Houk1999 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Famaey2005 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Luck2015 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference lang2006 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Prugniel2011 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. ^ "Naming Stars". IAU.org. Retrieved 16 December 2017.
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).