72 Leonis

72 Leonis
Location of 72 Leonis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Leo
Right ascension 11h 15m 12.22709s[1]
Declination +23° 05′ 43.8373″[1]
Apparent magnitude (V) 4.63[2]
Characteristics
Spectral type M3 IIb[3]
B−V color index 1.657±0.003[4]
Variable type LC[5]
Astrometry
Radial velocity (Rv)14.76±0.21[4] km/s
Proper motion (μ) RA: −25.56[1] mas/yr
Dec.: −6.00[1] mas/yr
Parallax (π)3.40 ± 0.65 mas[1]
Distanceapprox. 1,000 ly
(approx. 290 pc)
Absolute magnitude (MV)−2.69[4]
Details
Mass3.11[6] M☉
Radius195[6] R☉
Luminosity5,770[7] L☉
Surface gravity (log g)1.16[6] cgs
Temperature3,613±48[6] K
Metallicity [Fe/H]−0.03[6] dex
Age400[6] Myr
Other designations
72 Leo, FN Leo, BD+23°2322, FK5 2897, HD 97778, HIP 54951, HR 4362, SAO 81736[8]
Database references
SIMBADdata
The bright giant star 72 Leonis

72 Leonis is a single[9] variable star in the zodiac constellation of Leo, located roughly 1,000 light years away from the Sun.[1] It has the variable star designation FN Leonis; 72 Leonis is the Flamsteed designation. In Chinese astronomy, 72 Leonis is called 虎賁, Pinyin: Hǔbēn, meaning Emperor’s Bodyguard, because this star is marking itself and stands alone in the Emperor’s Bodyguard asterism, Supreme Palace enclosure mansion (see : Chinese constellation).[10]

This object is visible to the naked eye as a red-hued star with an apparent visual magnitude of 4.56.[4] It is an evolved bright giant with a stellar classification of M3 IIb and was listed as a spectral standard star for that class.[3] The star is classified as an irregular variable of type LC, ranging from Hipparcos magnitude 4.56 down to 4.64.[5] It has a radius 162 to 179[11] times that of the Sun and radiates 5,407[12] times the Sun's luminosity at an effective temperature of around 3,734 K.[13] The star is moving away from the Earth with a heliocentric radial velocity of 15 km/s.[4]

A light curve for FN Leonis, plotted from Hipparcos data [14]
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  4. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference baines2018 was invoked but never defined (see the help page).
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  14. ^ Cite error: The named reference HipDataAccess was invoked but never defined (see the help page).