Upsilon Leonis

υ Leonis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Leo
Right ascension 11h 36m 56.92983s[1]
Declination +00° 49′ 25.8758″[1]
Apparent magnitude (V) 4.33[2]
Characteristics
Spectral type G9 III[3]
U−B color index +0.76[2]
B−V color index +1.00[2]
Astrometry
Radial velocity (Rv)1.79±0.16[4] km/s
Proper motion (μ) RA: +1.76[1] mas/yr
Dec.: +43.37[1] mas/yr
Parallax (π)17.97 ± 0.22 mas[1]
Distance182 ± 2 ly
(55.6 ± 0.7 pc)
Absolute magnitude (MV)0.59[5]
Details
Mass2.58[5] M☉
Radius11[4] R☉
Luminosity56[4] L☉
Surface gravity (log g)2.7[4] cgs
Temperature4,842[4] K
Metallicity [Fe/H]–0.34[4] dex
Rotational velocity (v sin i)0.0[4] km/s
Age4.12±2.08[6] Gyr
Other designations
υ Leo, 91 Leo, BD−00°2458, FK5 437, HD 100920, HIP 56647, HR 4471, SAO 138298[7]
Database references
SIMBADdata

Upsilon Leonis (υ Leo) is a star in the zodiac constellation of Leo. It is visible to the naked eye with an apparent visual magnitude of 4.33.[2] The distance to this star, as determined using parallax measurements,[1] is about 182 light years. At that distance, the visual magnitude of the star is diminished by an estimated extinction factor of 0m.02 because of interstellar dust.[5]

With an age of around 4 billion years, this star has evolved into a G-type giant star with a stellar classification of G9 III.[3] It has 2.6 times the Sun's mass,[5] but has expanded to 11 times the solar radius and shines with 56 times the luminosity of the Sun at an effective temperature of 4,842 K.[4] The rate of rotation is too small to be measured, with a projected rotational velocity of 0.0 km/s.[4] The chemical abundance of elements other than hydrogen and helium, what astronomers term the star's metallicity, is less than half that in the Sun.[4] It is most likely a member of the galactic thin disk population.[6]

  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 Buscombe1962 was invoked but never defined (see the help page).
  4. ^ a b c d e f g h i j Cite error: The named reference aj135_1_209 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Takeda2005 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Soubiran2008 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).