39 Leonis

39 Leonis
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−B color index –0.05[5]
B−V color index +0.50[5]
Astrometry
Radial velocity (Rv)+37.4[6] km/s
Proper motion (μ) RA: −413.372 mas/yr[1]
Dec.: −98.047 mas/yr[1]
Parallax (π)44.9008 ± 0.0699 mas[1]
Distance72.6 ± 0.1 ly
(22.27 ± 0.03 pc)
Details
39 Leo A
Mass0.98[7] M☉
Radius0.99[8] R☉
Luminosity2.19[7] L☉
Surface gravity (log g)4.29±0.14[2] cgs
Temperature6,118±49[2] K
Metallicity [Fe/H]–0.27[2] dex
Rotational velocity (v sin i)2.16[9] km/s
Age6.3[2] Gyr
39 Leo B
Radius0.48[8] R☉
Surface gravity (log g)4.83±0.05[3] cgs
Temperature3,740±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
SIMBADdata

39 Leonis is the Flamsteed designation for a star in the zodiac constellation of Leo. It has an apparent visual magnitude of 5.90, so, according to the Bortle scale, it is faintly visible from suburban skies at night. Parallax measurements show an annual parallax shift of 0.0449″,[1] which is equivalent to a distance of around 72.6 ly (22.3 pc) from the Sun.

The stellar classification of 39 Leonis is F6 V,[4] indicating it is a main 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 a metal-poor star.[7] The effective temperature of the stellar atmosphere is 6,118 K,[2] giving it the yellow-white hued glow of an F-type star.[11]

Observations made with the Akari satellite at a wavelength of 18 μm show an excess of infrared emission. This suggests the presence of an inner debris disk orbiting the star at a distance greater than four astronomical units (AU). There was no significant excess found at 22 μm.[7]

A companion star is located at an angular separation of 7.72″ along a position angle of 302.7°—this corresponds to a projected separation of 175 AU.[12] It is a red dwarf star with a classification of M1 and an apparent visual magnitude of 11.40.[3]

  1. ^ a b c d e Cite error: The named reference GaiaEDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Maldonado2012 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Woolf2006 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Phillips2010 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Nordström2004 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference Fujiwara2013 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference CADARS was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Martínez-Arnáiz2010 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference csiro was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference ZapateroOsorio2004 was invoked but never defined (see the help page).