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] It is dedicated to the memory of Julio Cubillas, who died in December 2020, by the White Dwarf Research Corporation.[11]

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]
Distance	approx. 1,000 ly (approx. 290 pc)
Absolute magnitude (MV)	−2.69[4]
Details
Mass	3.11[6] M☉
Radius	195[6] R☉
Luminosity	5,770[7] L☉
Surface gravity (log g)	1.16[6] cgs
Temperature	3,613±48[6] K
Metallicity [Fe/H]	−0.03[6] dex
Age	400[6] Myr
Other designations
72 Leo, FN Leo, BD+23°2322, FK5 2897, HD 97778, HIP 54951, HR 4362, SAO 81736[8]
Database references
SIMBAD	data

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[12] times that of the Sun and radiates 5,407[13] times the Sun's luminosity at an effective temperature of around 3,734 K.[14] The star is moving away from the Earth with a heliocentric radial velocity of 15 km/s.[4]

References