HD 37124 is a star in the equatorial constellation of Taurus (the Bull), positioned about a half degree to the SSW of the bright star Zeta Tauri.[7] The apparent visual magnitude of this star is 7.68,[2] which is too dim to be visible to the naked eye. It is located at a distance of 103 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −23 km/s.[2] Three extrasolar planets have been found to orbit the star.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 05h 37m 02.4867s[1] |
| Declination | +20° 43′ 50.8346″[1] |
| Apparent magnitude (V) | 7.68[2] |
| Characteristics | |
| Spectral type | G4IV-V[3] |
| B−V color index | 0.667±0.008[2] |
| Astrometry | |
| Radial velocity (Rv) | −23.02±0.09[2] km/s |
| Proper motion (μ) | RA: −79.607±0.184[1] mas/yr Dec.: −420.161±0.166[1] mas/yr |
| Parallax (π) | 31.5536 ± 0.0751 mas[1] |
| Distance | 103.4 ± 0.2 ly (31.69 ± 0.08 pc) |
| Absolute magnitude (MV) | 5.05[2] |
| Details[4] | |
| Mass | 0.81±0.01 M☉[4] 0.92±0.01[5] M☉ |
| Radius | 0.92±0.02 R☉ 0.91+0.01 −0.04[1] R☉ |
| Luminosity | 0.839±0.003 L☉[4] 0.772+0.003 −0.002[1] L☉ |
| Surface gravity (log g) | 4.41±0.01 cgs |
| Temperature | 5,763±22 K |
| Metallicity [Fe/H] | −0.38±0.01 dex[2] −0.45[6] dex |
| Rotational velocity (v sin i) | 3.6[5] km/s |
| Age | 11.8±1.2 Gyr[4] 10.62±1.74[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The stellar classification of HD 37124 is G4IV-V, showing a spectrum with blended traits of a main sequence star and a more evolved subgiant star. It is a quiet star with a low activity index.[8] This star is smaller than the Sun, with 81–92% of the mass of the Sun and around 92% of the Sun's radius. It is an older, thick disk[9] star with an age of around 11 billion years, and is spinning with a projected rotational velocity of 3.6 km/s.[5] The metallicity of the star, what astronomers term the abundance of heavier elements, is much lower than in the Sun with an iron abundance of 35–41%. It is radiating 77–84% of the Sun's luminosity from its photosphere at an effective temperature of 5,763 K.
Planetary system
editAs of 2011, three extrasolar planets have been found to orbit the star. Announced on the first of November 1999, the first planet (HD 37124 b)[10][11] was discovered orbiting its parent star around the inner edge of the habitable zone, causing the planet to have a somewhat similar insolation to that of Venus. A second planet became apparent by 2003, thought to orbit in a 1940 days on an eccentric orbit,[12] but this was subsequently found to be unstable.[13] Solving this, a three-planet solution was announced in 2005:[14] this contained a second planet (HD 37124 c) orbiting at the outer edge of the habitable zone with an insolation similar to that of Mars, and a third planet, (HD 37124 d). While not obviously in any orbital resonances in 2005, an updated solution announced in 2011 found planets 'c' and 'd' to likely be in a 2:1 resonance.[15]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.675±0.017 MJ | 0.53364±0.00020 | 154.378±0.089 | 0.054±0.028 | — | — |
| c | ≥0.652±0.052 MJ | 1.7100±0.0065 | 885.5±5.1 | 0.125±0.055 | — | — |
| d | ≥0.69±0.059 MJ | 2.807±0.038 | 1,862±38 | 0.16±0.14 | — | — |
See also
editReferences
edit- ^ a b c d e f g 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.
- ^ a b c d e f g Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
- ^ a b "HD 37124". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2014-10-26.
- ^ a b c d Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951. S2CID 54555839.
- ^ a b c d Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. S2CID 119511744. 21.
- ^ Huang, C.; et al. (October 2005). "Chemical abundances of 22 extrasolar planet host stars*". Monthly Notices of the Royal Astronomical Society. 363 (1): 71–78. Bibcode:2005MNRAS.363...71H. doi:10.1111/j.1365-2966.2005.09395.x.
- ^ Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 1. Sky Publishing Corporation and the European Space Agency. p. 182. ISBN 0-933346-84-0.
- ^ Goździewski, Krzysztof; et al. (July 2006). "Orbital Configurations and Dynamical Stability of Multiplanet Systems around Sun-like Stars HD 202206, 14 Herculis, HD 37124, and HD 108874". The Astrophysical Journal. 645 (1): 688–703. arXiv:astro-ph/0511463. Bibcode:2006ApJ...645..688G. doi:10.1086/504030. S2CID 15012577.
- ^ Gonzalez, Guillermo (October 2009). "Stars with planets and the thick disc". Monthly Notices of the Royal Astronomical Society: Letters. 399 (1): L103–L107. Bibcode:2009MNRAS.399L.103G. doi:10.1111/j.1745-3933.2009.00734.x.
- ^ "Astronomers discover six new planets orbiting nearby stars" (Press release). Kamuela, Hawaii: W. M. Keck Observatory. November 1, 1999. Retrieved December 19, 2017.
- ^ Vogt, Steven S.; et al. (2000). "Six New Planets from the Keck Precision Velocity Survey". The Astrophysical Journal. 536 (2): 902–914. arXiv:astro-ph/9911506. Bibcode:2000ApJ...536..902V. doi:10.1086/308981. S2CID 119375519.
- ^ Butler, R. Paul; et al. (2003). "Seven New Keck Planets Orbiting G and K Dwarfs". The Astrophysical Journal. 582 (1): 455–466. Bibcode:2003ApJ...582..455B. CiteSeerX 10.1.1.7.6988. doi:10.1086/344570. S2CID 17608922.
- ^ Goźdiewski, K. (2003). "A dynamical analysis of the HD 37124 planetary system". Astronomy and Astrophysics. 398 (1): 315–325. Bibcode:2003A&A...398..315G. doi:10.1051/0004-6361:20021602.
- ^ Vogt, Steven S.; et al. (2005). "Five New Multicomponent Planetary Systems" (PDF). The Astrophysical Journal. 632 (1): 638–658. Bibcode:2005ApJ...632..638V. doi:10.1086/432901. S2CID 16509245. Retrieved 2020-12-11.
- ^ a b Wright, J. T.; et al. (2011). "The California Planet Survey. III. A Possible 2:1 Resonance in the Exoplanetary Triple System HD 37124". The Astrophysical Journal. 730 (2): 61–145. arXiv:1101.1097. Bibcode:2011ApJ...730...93W. doi:10.1088/0004-637X/730/2/93. S2CID 119273897.
External links
edit- Jianghui Ji; et al. (2003-05-23). "The Librating Companions in HD 37124, HD 12661, HD 82943, 47 Uma and GJ 876: Alignment or Antialignment?". The Astrophysical Journal. 591 (1): L57–L60. arXiv:astro-ph/0305448. Bibcode:2003ApJ...591L..57J. doi:10.1086/377038. S2CID 12743267.
- "Notes for star HD 37124". Extrasolar Planets Encyclopaedia. Archived from the original on November 6, 2007. Retrieved 2008-06-22.