Tau Leonis

τ Leonis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Leo
Right ascension 11h 27m 56.23976s[1]
Declination +02° 51′ 22.5609″[1]
Apparent magnitude (V) 5.00[2]
Characteristics
Spectral type G8- IIIa[3]
U−B color index +0.80[2]
B−V color index +1.005[2]
Astrometry
Radial velocity (Rv)−8.90[4] km/s
Proper motion (μ) RA: +16.89[1] mas/yr
Dec.: −9.81[1] mas/yr
Parallax (π)5.80 ± 0.33 mas[1]
Distance560 ± 30 ly
(172 ± 10 pc)
Absolute magnitude (MV)−1.12±0.124[5]
Details
Mass3.90±0.19[6] M☉
Radius25.14±1.55[6] R☉
Luminosity329.6±39.6[6] L☉
Surface gravity (log g)2.25±0.05[6] cgs
Temperature4,910±33[6] K
Metallicity [Fe/H]−0.07±0.10[6] dex
Age190±20[6] Myr
Other designations
τ Leo, 84 Leo, BD+03°2504, FK5 1297, HD 99648, HIP 55945, HR 4418, SAO 118875[7]
Database references
SIMBADdata

Tau Leonis (τ Leo) is a star in the zodiac constellation of Leo. Because it is located near the ecliptic, it is subject to occultations by the Moon.[8] It has an apparent visual magnitude of 5.00,[2] which is bright enough to be seen with the naked eye. The distance to this star, as estimated using parallax measurements,[1] is 560 light years. It is moving closer to the Sun with a radial velocity of −9 km/s.[4]

This G-type giant star has a stellar classification of G8- IIIa[3] and currently resides on the red giant branch. It has about 390% of the Sun's mass. The star is much younger than the Sun, with an age of around 190 million years. As an evolved giant, it has expanded to about 25 times the Sun's radius and radiates 330 times the luminosity of the Sun. The effective temperature of the outer atmosphere is 4,910 K.[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 Keenan1989 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference aa546_A61 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference park2013 was invoked but never defined (see the help page).
  6. ^ a b c d e f g h Cite error: The named reference Hekker2007 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 Richichi2017 was invoked but never defined (see the help page).