20 Leonis Minoris
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Leo Minor |
| Right ascension | 10h 01m 00.65688s[1] |
| Declination | +31° 55′ 25.2130″[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: −528.871(92) mas/yr[1] Dec.: −429.376(74) mas/yr[1] |
| Parallax (π) | 66.9958 ± 0.0921 mas[1] |
| Distance | 48.68 ± 0.07 ly (14.93 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.46[7] |
| Details | |
| 20 LMi A | |
| Mass | 0.967±0.010[8] M☉ |
| Radius | 1.237±0.019[8] R☉ |
| Luminosity | 1.365±0.014[8] L☉ |
| Surface gravity (log g) | 4.25±0.02[8] cgs |
| Temperature | 5,735±5.6[9] K |
| Metallicity [Fe/H] | 0.20±0.02[8] dex |
| Rotation | 10.64±0.14 d[2] |
| Rotational velocity (v sin i) | 2.4±0.5[8] km/s |
| Age | 6.2–7.7[10] Gyr |
| 20 LMi B | |
| Mass | 0.11[11] M☉ |
| Rotation | 19.2687 d[4] |
| Other designations | |
| 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 Hδ1.[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
[edit]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 ME and an orbital period of 31 days, this is most likely a hot Neptune-type planet.[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
[edit]- ^ 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
[edit]- "4C00774". ARICNS. Archived from the original on 2011-06-07. Retrieved 2006-07-31.
