20 Leonis Minoris

20 Leonis Minoris
Observation data
Epoch J2000      Equinox J2000
Constellation Leo Minor
Right ascension 10h 01m 00.65765s[1]
Declination +31° 55′ 25.2151″[1]
Apparent magnitude (V) +5.40[2]
Characteristics
Spectral type G3 Va Hδ1[3] + M7 V[4]
U−B color index +0.27[5]
B−V color index +0.65[5]
Astrometry
Radial velocity (Rv)+55.96±0.09[6] km/s
Proper motion (μ) RA: −527.63±0.30[1] mas/yr
Dec.: −429.42±0.18[1] mas/yr
Parallax (π)66.46 ± 0.32 mas[1]
Distance49.1 ± 0.2 ly
(15.05 ± 0.07 pc)
Absolute magnitude (MV)4.46[7]
Details
20 LMi A
Mass1.12[8] M☉
Radius1.247±0.021[9] R☉
Luminosity1.378±0.027[9] L☉
Temperature5,735±5.6[10] K
Rotation10.64±0.14 d[2]
Age6.2–7.7[11] Gyr
20 LMi B
Mass0.11[8] M☉
Rotation19.2687 d[4]
Other designations
20 LMi, BD+32° 1964, FK5 1258, GJ 376, HD 86728, HIP 49081, HR 3951, SAO 61808, LHS 2216, LTT 12671[12]
Database references
SIMBADdata

20 Leonis Minoris is a binary star system in the northern constellation of Leo Minor. It is faintly visible to the naked eye, having an apparent visual magnitude of +5.4.[2] Based upon an annual parallax shift of 66.46 mas, it is located 49 light years from the Sun. The star has a relatively high proper motion[3] and is moving away from the Sun with a radial velocity of +56 km/s.[6] The system made its closest approach about 150,000 years ago when it came within 32.2 ly (9.86 pc).[13]

The primary member of this system is a G-type main-sequence star with a stellar classification of G3 Va Hδ1.[3] It has 12% more mass and a 25% larger radius than the Sun. The star is about seven[11] billion years old and is spinning with a rotation period of 10.6 days.[2] The small companion is an active red dwarf star that has a relatively high metallicity.[14] The two stars are currently separated by 14.5 arc seconds, corresponding to a projected separation of 2016 AU.[8]

In 2020, a candidate exoplanet was detected orbiting 20 Leonis Minoris (HD 86728). With a minimum mass of 0.032 MJ (10.2 ME) and an orbital period of 31 days, this would most likely be a hot Neptune.[15]

The 20 Leonis Minoris planetary system[15]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b (unconfirmed) ≥0.032+0.005
−0.005 MJ 		0.2003+0.00007
−0.00007 		31.15+0.02
−0.02 		0.2+0.2
−0.1 		— —
  1. ^ a b c d e Cite error: The named reference hipparcos was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Hempelmann2016 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Keenan1989 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference West2015 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference EgUBV was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Holmberg2009 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Tokovinin2016 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference apj746_1_101 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference aaa411_3_559 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference apj687 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference BailerJones2015 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference mnras311_2_385 was invoked but never defined (see the help page).
  15. ^ a b Cite error: The named reference Hirsch2020 was invoked but never defined (see the help page).