11 Leonis Minoris

11 Leonis Minoris is a binary star[2] located 36.5 light years away from Earth,[1] in the northern constellation of Leo Minor.[10] It is visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.54.[2] The system is moving away from the Earth with a heliocentric radial velocity of +14.4 km/s.[5] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.764 arc seconds per annum.[11]

11 Leonis Minoris A/B
Observation data
Epoch J2000      Equinox J2000
Constellation Leo Minor
Right ascension  09h 35m 39.50181s[1]
Declination +35° 48′ 36.4841″[1]
Apparent magnitude (V) 5.54 + 14.0[2]
Characteristics
Spectral type G8V[3] + M4[4]
U−B color index 0.44/—
B−V color index 0.77/—
Variable type RS CVn
Astrometry
Radial velocity (Rv)+14.40[5] km/s
Proper motion (μ) RA: −726.201[1] mas/yr
Dec.: −259.506[1] mas/yr
Parallax (π)89.2581 ± 0.1928[1] mas
Distance36.54 ± 0.08 ly
(11.20 ± 0.02 pc)
Absolute magnitude (MV)5.25±0.008[6]
Orbit[3]
Companion11 LMi B
Period (P)201 yr
Semi-major axis (a)3.84″
Eccentricity (e)0.88
Inclination (i)117°
Details
11 LMi A
Mass0.964[7] M☉
Radius1.0029±0.0158[7] R☉
Luminosity0.7550±0.0055[7] L☉
Temperature5376±43[7] K
Metallicity [Fe/H]+0.33[8] dex
Rotation18.0 days[8]
Age7.9[7] Gyr
11 LMi B
Mass0.23[9] M☉
Other designations
11 LMi, BD+36°1979, GJ 356, HD 82885, HIP 47080, HR 3815, SAO 61586, WDS 09357+3549[10]
Database references
SIMBAD11 LMi A
11 LMi B
ARICNS11 LMi A
11 LMi B

The primary component is a G-type main-sequence star with a stellar classification of G8V,[3] which is slightly less massive and slightly dimmer than the Sun.[7] This is an RS Canum Venaticorum variable star with its luminosity varying by 0.033 magnitudes over a period of 18 days.[12] Compared to the Sun, it has more than double the abundance of elements more massive than helium—what astronomers term the star's metallicity.[8]

There is a secondary component, a 14th[2] magnitude red dwarf star much dimmer than the primary. The pair have an orbital period of 201 years with a high eccentricity of 0.88.[3]

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
  3. Malkov, O. Yu.; et al. (2012), "Dynamical masses of a selected sample of orbital binaries", Astronomy & Astrophysics, 546: 5, Bibcode:2012A&A...546A..69M, doi:10.1051/0004-6361/201219774, A69
  4. Reid, I. Neill; et al. (July 2004), "Meeting the Cool Neighbors. VIII. A Preliminary 20 Parsec Census from the NLTT Catalogue", The Astronomical Journal, 128 (1): 463–483, arXiv:astro-ph/0404061, Bibcode:2004AJ....128..463R, doi:10.1086/421374
  5. Soubiran, C.; et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics, 480 (1): 91–101, arXiv:0712.1370, Bibcode:2008A&A...480...91S, doi:10.1051/0004-6361:20078788
  6. Park, Sunkyung; et al. (2013), "Wilson-Bappu Effect: Extended to Surface Gravity", The Astronomical Journal, 146 (4): 73, arXiv:1307.0592, Bibcode:2013AJ....146...73P, doi:10.1088/0004-6256/146/4/73.
  7. Boyajian, Tabetha S.; et al. (July 2013), "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations", The Astrophysical Journal, 771 (1): 40, arXiv:1306.2974, Bibcode:2013ApJ...771...40B, doi:10.1088/0004-637X/771/1/40.
  8. Maldonado, J.; et al. (October 2010), "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups", Astronomy and Astrophysics, 521: A12, arXiv:1007.1132, Bibcode:2010A&A...521A..12M, doi:10.1051/0004-6361/201014948
  9. Tokovinin, Andrei (April 2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, arXiv:1401.6827, Bibcode:2014AJ....147...87T, doi:10.1088/0004-6256/147/4/87, 87.
  10. "* 11 LMi". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-06-02.
  11. Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal, 129 (3): 1483–1522, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854.
  12. Skiff, B. A.; et al. (March 1986), "The photometric variability of solar-type stars. V - The standard stars 10 and 11 Leonis Minoris", Publications of the Astronomical Society of the Pacific, 98: 338–341, Bibcode:1986PASP...98..338S, doi:10.1086/131763
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