| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Leo |
| Right ascension | 10h 17m 14.538s[1] |
| Declination | +23° 06′ 22.38″[1] |
| Apparent magnitude (V) | 5.81[2]/11.40[3] |
| Characteristics | |
| Spectral type | F6 V[4] + M1[3] |
| U−Bcolor index | –0.05[5] |
| B−Vcolor index | +0.50[5] |
| Astrometry | |
| Radial velocity (Rv) | +37.4[6] km/s |
| Proper motion (μ) | RA: −413.372mas/yr[1] Dec.: −98.047mas/yr[1] |
| Parallax (π) | 44.9008±0.0699 mas[1] |
| Distance | 72.6 ± 0.1 ly (22.27 ± 0.03 pc) |
| Details | |
| 39 Leo A | |
| Mass | 0.98[7] M☉ |
| Radius | 0.99[8] R☉ |
| Luminosity | 2.19[7] L☉ |
| Surface gravity (log g) | 4.29±0.14[2] cgs |
| Temperature | 6,118±49[2] K |
| Metallicity [Fe/H] | –0.27[2] dex |
| Rotational velocity (v sin i) | 2.16[9] km/s |
| Age | 6.3[2] Gyr |
| 39 Leo B | |
| Radius | 0.48[8] R☉ |
| Surface gravity (log g) | 4.83±0.05[3] cgs |
| Temperature | 3,740±40[3] K |
| Metallicity [Fe/H] | −0.33±0.06[3] dex |
| Other designations | |
| 39 Leo,BD+23 2207,GJ 387,HD 89125,HIP 50384,HR 4039,SAO 81270[10] | |
| Database references | |
| SIMBAD | data |
39 Leonis is theFlamsteed designation for a star in thezodiacconstellation ofLeo. It has anapparent visual magnitude of 5.90, so, according to theBortle scale, it is faintly visible from suburban skies at night.Parallax measurements show an annualparallax shift of 0.0449″,[1] which is equivalent to a distance of around 72.6 ly (22.3 pc) from the Sun.
Thestellar classification of 39 Leonis is F6 V,[4] indicating it is amain sequence star. It shines with a luminosity more than double that of the Sun, although it has nearly the same mass and size.[7][8] This is a mature star with an estimated age of 6.3 billion years. The abundance of elements other than hydrogen and helium is about half that in the Sun, making this ametal-poor star.[7] Theeffective temperature of thestellar atmosphere is 6,118 K,[2] giving it the yellow-white hued glow of anF-type star.[11]
Observations made with theAkari satellite at a wavelength of 18 μm show anexcess of infrared emission. This suggests the presence of an innerdebris disk orbiting the star at a distance greater than fourastronomical units (AU). There was no significant excess found at 22 μm.[7]
A companion star is located at anangular separation of 7.72″ along aposition angle of 302.7°—this corresponds to aprojected separation of 175 AU.[12] It is ared dwarf star with a classification of M1 and an apparent visual magnitude of 11.40.[3]
