20 Leonis Minoris

20 Leonis Minoris
Observation data; Epoch J2000 Equinox J2000
Constellation	Leo Minor
Right ascension	10h 01m 00.65688s
Declination	+31° 55′ 25.2130″
Apparent magnitude (V)	+5.40
Characteristics
Spectral type	G3 Va Hδ1 + M7 V
U−B color index	+0.27
B−V color index	+0.65
Astrometry
Radial velocity (Rv)	+55.96±0.09 km/s
Proper motion (μ)	RA: −528.871(92) mas/yr ; Dec.: −429.376(74) mas/yr
Parallax (π)	66.9958 ± 0.0921 mas
Distance	48.68 ± 0.07 ly ; (14.93 ± 0.02 pc)
Absolute magnitude (MV)	4.46
Details
20 LMi A
Mass	0.967±0.010 M☉
Radius	1.237±0.019 R☉
Luminosity	1.365±0.014 L☉
Surface gravity (log g)	4.25±0.02 cgs
Temperature	5,735±5.6 K
Metallicity [Fe/H]	0.20±0.02 dex
Rotation	10.64±0.14 d
Rotational velocity (v sin i)	2.4±0.5 km/s
Age	6.2–7.7 Gyr
20 LMi B
Mass	0.11 M☉
Rotation	19.2687 d
Other designations
	20 LMi, BD+32° 1964, FK5 1258, GJ 376, HD 86728, HIP 49081, HR 3951, SAO 61808, LHS 2216, LTT 12671
Database references
SIMBAD	data

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 66.996 mas, it is located 48.7 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 H_δ1.^[3] It has 12% more mass and a 25% larger radius than the Sun. The star is about seven^[10] 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.^[11]

Planetary system

A candidate exoplanet orbiting 20 Leonis Minoris A (HD 86728) was first detected in 2020,^[15] and confirmed in 2024 as the first discovery of the NEID Earth Twin Survey (NETS). With a minimum mass of 9.2 M_E and an orbital period of 31 days, this is most likely a hot Neptune-type planet.^[8]

The 20 Leonis Minoris A planetary system^[8]
Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥9.16+0.55 −0.56 $M$ _🜨	0.1916+0.00065 −0.00066	31.1503+0.0062 −0.0066	0.064+0.065 −0.044	—	—

References

^ ^a ^b ^c ^d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
^ ^a ^b ^c ^d Hempelmann, A.; et al. (February 2016), "Measuring rotation periods of solar-like stars using TIGRE. A study of periodic CaII H+K S-index variability", Astronomy & Astrophysics, 586: 19, Bibcode:2016A&A...586A..14H, doi:10.1051/0004-6361/201526972, A14.
^ ^a ^b ^c Keenan, P.; McNeil, R. (October 1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245–266, Bibcode:1989ApJS...71..245K, doi:10.1086/191373, S2CID 123149047.
^ ^a ^b West, Andrew A.; et al. (October 2015), "An Activity-Rotation Relationship and Kinematic Analysis of Nearby Mid-to-Late-Type M Dwarfs", The Astrophysical Journal, 812 (1): 12, arXiv:1509.01590, Bibcode:2015ApJ...812....3W, doi:10.1088/0004-637X/812/1/3, S2CID 17434970, 3.
^ ^a ^b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
^ ^a ^b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
^ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
^ ^a ^b ^c ^d ^e ^f ^g ^h Gupta, Arvind F.; Luhn, Jacob K.; et al. (December 2024). "The NEID Earth Twin Survey. I. Confirmation of a 31 Day Planet Orbiting HD 86728". The Astronomical Journal. 169 (1): 1. arXiv:2409.12315. Bibcode:2025AJ....169....1G. doi:10.3847/1538-3881/ad89bf.
^ Kovtyukh; Soubiran, C.; Belik, S. I.; Gorlova, N. I. (2003), "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios", Astronomy and Astrophysics, 411 (3): 559–564, arXiv:astro-ph/0308429, Bibcode:2003A&A...411..559K, doi:10.1051/0004-6361:20031378, S2CID 18478960
^ ^a ^b Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785, S2CID 27151456
^ ^a ^b Tokovinin, A.; Kiyaeva, O. (February 2016), "Eccentricity distribution of wide binaries", Monthly Notices of the Royal Astronomical Society, 456 (2): 2070−2079, arXiv:1512.00278, Bibcode:2016MNRAS.456.2070T, doi:10.1093/mnras/stv2825, S2CID 1615080.
^ "HD 86728". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-07-31.
^ Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics, 575: 13, arXiv:1412.3648, Bibcode:2015A&A...575A..35B, doi:10.1051/0004-6361/201425221, S2CID 59039482, A35.
^ Gizis, J. E.; et al. (2000), "Two Nearby M Dwarf Binaries from 2MASS" (PDF), Monthly Notices of the Royal Astronomical Society, 311 (2): 385, Bibcode:2000MNRAS.311..385G, doi:10.1046/j.1365-8711.2000.03060.x
^ Hirsch, Lea A.; et al. (2021), "Understanding the Impacts of Stellar Companions on Planet Formation and Evolution: A Survey of Stellar and Planetary Companions within 25 pc", The Astronomical Journal, 161 (3): 134, arXiv:2012.09190, Bibcode:2021AJ....161..134H, doi:10.3847/1538-3881/abd639, S2CID 229297873.

External links

"4C00774". ARICNS. Archived from the original on 2011-06-07. Retrieved 2006-07-31.

[GaiaDR3-1] Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.

[Hempelmann2016-2] Hempelmann, A.; et al. (February 2016), "Measuring rotation periods of solar-like stars using TIGRE. A study of periodic CaII H+K S-index variability", Astronomy & Astrophysics, 586: 19, Bibcode:2016A&A...586A..14H, doi:10.1051/0004-6361/201526972, A14.

[Keenan1989-3] Keenan, P.; McNeil, R. (October 1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245–266, Bibcode:1989ApJS...71..245K, doi:10.1086/191373, S2CID 123149047.

[West2015-4] West, Andrew A.; et al. (October 2015), "An Activity-Rotation Relationship and Kinematic Analysis of Nearby Mid-to-Late-Type M Dwarfs", The Astrophysical Journal, 812 (1): 12, arXiv:1509.01590, Bibcode:2015ApJ...812....3W, doi:10.1088/0004-637X/812/1/3, S2CID 17434970, 3.

[EgUBV-5] Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.

[Gontcharov-6] Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.

[Holmberg2009-7] Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.

[Gupta2024-8] ^ ^a ^b ^c ^d ^e ^f ^g ^h Gupta, Arvind F.; Luhn, Jacob K.; et al. (December 2024). "The NEID Earth Twin Survey. I. Confirmation of a 31 Day Planet Orbiting HD 86728". The Astronomical Journal. 169 (1): 1. arXiv:2409.12315. Bibcode:2025AJ....169....1G. doi:10.3847/1538-3881/ad89bf.

[aaa411_3_559-9] Kovtyukh; Soubiran, C.; Belik, S. I.; Gorlova, N. I. (2003), "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios", Astronomy and Astrophysics, 411 (3): 559–564, arXiv:astro-ph/0308429, Bibcode:2003A&A...411..559K, doi:10.1051/0004-6361:20031378, S2CID 18478960

[apj687-10] Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785, S2CID 27151456

[Tokovinin2016-11] Tokovinin, A.; Kiyaeva, O. (February 2016), "Eccentricity distribution of wide binaries", Monthly Notices of the Royal Astronomical Society, 456 (2): 2070−2079, arXiv:1512.00278, Bibcode:2016MNRAS.456.2070T, doi:10.1093/mnras/stv2825, S2CID 1615080.

[SIMBAD-12] "HD 86728". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-07-31.

[BailerJones2015-13] Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics, 575: 13, arXiv:1412.3648, Bibcode:2015A&A...575A..35B, doi:10.1051/0004-6361/201425221, S2CID 59039482, A35.

[mnras311_2_385-14] Gizis, J. E.; et al. (2000), "Two Nearby M Dwarf Binaries from 2MASS" (PDF), Monthly Notices of the Royal Astronomical Society, 311 (2): 385, Bibcode:2000MNRAS.311..385G, doi:10.1046/j.1365-8711.2000.03060.x

[Hirsch2020-15] Hirsch, Lea A.; et al. (2021), "Understanding the Impacts of Stellar Companions on Planet Formation and Evolution: A Survey of Stellar and Planetary Companions within 25 pc", The Astronomical Journal, 161 (3): 134, arXiv:2012.09190, Bibcode:2021AJ....161..134H, doi:10.3847/1538-3881/abd639, S2CID 229297873.

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20 Leonis Minoris

Planetary system

References

External links

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