72 Leonis
Single, variable M-type giant star in the constellation Leo
From Wikipedia, the free encyclopedia
72 Leonis is a single[11] variable star in the zodiac constellation of Leo, located roughly 760 light years away.[2] 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).[12]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Leo[1] |
| Right ascension | 11h 15m 12.22839s[2] |
| Declination | +23° 05′ 43.8322″[2] |
| Apparent magnitude (V) | 4.63[3] |
| Characteristics | |
| Evolutionary stage | AGB[4] |
| Spectral type | M3 IIb[5] |
| B−V color index | 1.657±0.003[1] |
| Variable type | LC[6] |
| Astrometry | |
| Radial velocity (Rv) | 14.76±0.21[1] km/s |
| Proper motion (μ) | RA: −25.612 mas/yr[2] Dec.: −5.995 mas/yr[2] |
| Parallax (π) | 4.2936±0.2815 mas[2] |
| Distance | 760 ± 50 ly (230 ± 20 pc) |
| Absolute magnitude (MV) | −2.69[1] |
| Details | |
| Mass | 3.11[7] M☉ |
| Radius | 149+9 −10[8] R☉ |
| Luminosity | 5,770[9] L☉ |
| Surface gravity (log g) | 1.16[7] cgs |
| Temperature | 3,613±48[7] K |
| Metallicity [Fe/H] | −0.03[7] dex |
| Age | 400[7] Myr |
| Other designations | |
| 72 Leo, FN Leo, AAVSO 1109+23, BD+23°2322, FK5 2897, HD 97778, HIP 54951, HR 4362, SAO 81736[10] | |
| 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.[1] It is an evolved bright giant with a stellar classification of M3 IIb and was listed as a spectral standard star for that class.[5] The star is classified as an irregular variable of type LC, ranging from Hipparcos magnitude 4.56 down to 4.64.[6] It has a radius 150 times that of the Sun[8] and radiates 5,770 times the Sun's luminosity[9] at an effective temperature of around 3,613 K.[7] The star is moving away from the Earth with a heliocentric radial velocity of 15 km/s.[1]
