Upsilon1 Eridani

For other star systems with this Bayer designation, see Upsilon Eridani.
υ1 Eridanian
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 04h 33m 30.55236s[1]
Declination −29° 45′ 59.3725″[1]
Apparent magnitude (V) 4.51[2]
Characteristics
Spectral type K0 III-IV[3]
U−B color index +0.70[2]
B−V color index +0.98[2]
Astrometry
Radial velocity (Rv)+20.89±0.69[4] km/s
Proper motion (μ) RA: −114.78[1] mas/yr
Dec.: −271.79[1] mas/yr
Parallax (π)25.67 ± 0.24 mas[1]
Distance127 ± 1 ly
(39.0 ± 0.4 pc)
Absolute magnitude (MV)1.60[4]
Details
Mass1.54[4] M☉
Radius7.3[5] R☉
Luminosity24[4] L☉
Surface gravity (log g)3.09[4] cgs
Temperature4,941[4] K
Metallicity [Fe/H]−0.16±0.08[4] dex
Rotational velocity (v sin i)2.15[6] km/s
Other designations
υ1 Eridani, υ1 Eri, 50 Eridani, CD−30° 1883, HD 29085, HIP 21248, HR 1453, SAO 169570.[7]
Database references
SIMBADdata

Upsilon1 Eridani (υ1 Eri) is a single star in the constellation Eridanus. It has an apparent visual magnitude is 4.51,[2] which is bright enough to be faintly visible to the naked eye on a clear, dark night. The distance to this star, as determined using the parallax method,[1] is around 127 light years.

This is an evolved red clump[8] giant star with a stellar classification of K0III-IV.[3] The measured angular diameter, after correction for limb darkening, is 1.74±0.02 mas.[9] At an estimated distance of this star, this yields a physical size of about 7.3 times the radius of the Sun.[5] It has 154%[4] of the Sun's mass and radiates 24 times the solar luminosity from its outer atmosphere at an effective temperature of 4,941 K.[4]

  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. ^ a b Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  4. ^ a b c d e f g h i Cite error: The named reference Luck2007 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference lang2006 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference hekker was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Alves2000 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Richichi2005 was invoked but never defined (see the help page).