Astronomy:38 Leonis Minoris
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Leo Minor |
| Right ascension | 10h 39m 07.63244s[1] |
| Declination | +37° 54′ 36.0035″[1] |
| Apparent magnitude (V) | 5.84[2] |
| Characteristics | |
| Spectral type | G0 IV[3] |
| B−V color index | 0.595±0.003[2] |
| Astrometry | |
| Radial velocity (Rv) | +30.9±0.3[4] km/s |
| Proper motion (μ) | RA: −220.50[1] mas/yr Dec.: −45.31[1] mas/yr |
| Parallax (π) | 19.11 ± 0.37[1] mas |
| Distance | 171 ± 3 ly (52 ± 1 pc) |
| Absolute magnitude (MV) | 2.26[5] |
| Orbit[5] | |
| Period (P) | 7.7991499±0.0000037 d |
| Eccentricity (e) | 0.023±0.034 |
| Periastron epoch (T) | 20,165.164±1.470 HJD |
| Argument of periastron (ω) (secondary) | 285.56±68.51° |
| Semi-amplitude (K1) (primary) | 24.10±0.73 km/s |
| Details | |
| 38 LMi A | |
| Mass | 1.68[6] M☉ |
| Luminosity | 11.32[2] L☉ |
| Surface gravity (log g) | 3.73[6] cgs |
| Temperature | 6,106[7] K |
| Metallicity [Fe/H] | +0.32[7] dex |
| Rotational velocity (v sin i) | 14.5±1.0[5] km/s |
| Age | 2.03±0.14[7] Gyr |
| 38 LMi B | |
| Mass | ≥ 0.31[8] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
38 Leonis Minoris is a binary star[3] system in the northern constellation of Leo Minor. It shines with a combined light of apparent magnitude 5.84,[2] which indicates it a dimly visible to the naked eye under good viewing conditions. An annual parallax shift of 19.11[1] mas provides a distance estimate of around 171 light years. It has a relatively high proper motion, traversing the celestial sphere at a rate of 0.226 arcseconds per year,[10] and is moving away from the Sun with a radial velocity of +31 km/s.[4]
This is a single-lined spectroscopic binary[3] with an orbital period of 7.8 days and a low eccentricity of 0.023 – nearly circular.[5] The visible component has a stellar classification of G0 IV,[3] matching a G-type subgiant star that is exhausting the hydrogen at its core and evolving into a giant. It is about two[7] billion years old with 1.68[6] times the mass of the Sun and is spinning with a projected rotational velocity of 14.5 km/s.[5] The star has a higher than solar abundance of iron in its spectrum.[7] It is radiating 11[2] times the Sun's luminosity from its photosphere at an effective temperature of 6,106 K.[7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 3.3 Abt, Helmut A. (2009), "MK Classifications of Spectroscopic Binaries", The Astrophysical Journal Supplement 180 (1): 117–18, doi:10.1088/0067-0049/180/1/117, Bibcode: 2009ApJS..180..117A.
- ↑ 4.0 4.1 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 5.0 5.1 5.2 5.3 5.4 Willmarth, Daryl W. et al. (August 2016), "Spectroscopic Orbits for 15 Late-type Stars", The Astronomical Journal 152 (2): 13, doi:10.3847/0004-6256/152/2/46, 46, Bibcode: 2016AJ....152...46W, https://dipot.ulb.ac.be/dspace/bitstream/2013/236718/3/Willmarth_2016_AJ_152_46.pdf.
- ↑ 6.0 6.1 6.2 Casagrande, L. et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics 530: A138, doi:10.1051/0004-6361/201016276, Bibcode: 2011A&A...530A.138C.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics 551: 4, doi:10.1051/0004-6361/201220364, L8, Bibcode: 2013A&A...551L...8P.
- ↑ Tokovinin, A. et al. (May 2006), "Tertiary companions to close spectroscopic binaries", Astronomy and Astrophysics 450 (2): 681–69, doi:10.1051/0004-6361:20054427, Bibcode: 2006A&A...450..681T.
- ↑ "38 LMi". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=38+LMi.
- ↑ 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, doi:10.1086/427854, Bibcode: 2005AJ....129.1483L.
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