Zeta Eridani

ζ Eridani
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 03h 15m 50.02656s[1]
Declination −08° 49′ 11.0220″[1]
Apparent magnitude (V) 4.80[2]
Characteristics
Spectral type kA4hA9mA9V[3]
U−B color index +0.07[2]
B−V color index +0.24[2]
Astrometry
Radial velocity (Rv)−5.8±4.2[4] km/s
Proper motion (μ) RA: −0.35[1] mas/yr
Dec.: +46.10[1] mas/yr
Parallax (π)29.72 ± 0.29 mas[1]
Distance110 ± 1 ly
(33.6 ± 0.3 pc)
Absolute magnitude (MV)1.97[5]
Orbit[6]
Period (P)17.9297±0.0039 d
Eccentricity (e)0.14±0.03
Periastron epoch (T)43,051.07±0.83 JD
Argument of periastron (ω)
(secondary)		122±11°
Semi-amplitude (K1)
(primary)		21.5±0.6 km/s
Details
Mass1.85[7] M☉
Radius10.3[7] R☉
Luminosity10.3[8] L☉
Surface gravity (log g)4.05[7] cgs
Temperature7,575[7] K
Metallicity [Fe/H]0.04[7] dex
Rotational velocity (v sin i)82[5] km/s
Age800[9] Myr
Other designations
Zibal, ζ Eri, 13 Eri, FK5 1091, HD 20320, HIP 15197, HR 984, SAO 130387, BD−09° 624, WDS J03158-0849A[10]
Database references
SIMBADdata

Zeta Eridani (ζ Eridani, abbreviated Zeta Eri, ζ Eri) is a binary star in the constellation of Eridanus. With an apparent visual magnitude of 4.80,[2] it is visible to the naked eye on a clear dark night. Based on parallax measurements taken during the Hipparcos mission, it is approximately 110 light-years from the Sun.

Zeta Eridani is the primary or 'A' component of a multiple star system designated WDS J03158-0849 (the secondary or 'B' component is 14 Eridani).[11] Zeta Eridani's two components are therefore designated WDS J03158-0849 Aa and Ab. Aa is formally named Zibal /ˈzaɪbəl/, the traditional name for the system.[12]

  1. ^ a b c d e 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 Gray2006 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Iliev2006 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Abt1985 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference Pawellek2014 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Vican2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ "Washington Double Star Catalog". United States Naval Observatory. Retrieved 23 February 2018.
  12. ^ Cite error: The named reference IAU-LSN was invoked but never defined (see the help page).