HD 4203 is a single star in the equatorial constellation of Pisces, near the northern constellation border with Andromeda. It has a yellow hue and is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.70.[2] The distance to this object is 266 light years based on parallax,[1] but it is drifting closer to the Sun with a radial velocity of −14 km/s.[2]

HD 4203
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pisces
Right ascension 00h 44m 41.2003s[1]
Declination +20° 26′ 56.1380″[1]
Apparent magnitude (V) 8.70[2]
Characteristics
Spectral type G5V[3]
B−V color index +0.771±0.021[2]
Astrometry
Radial velocity (Rv)−14.20±0.09[2] km/s
Proper motion (μ) RA: +122.070±0.102[1] mas/yr
Dec.: −124.192±0.062[1] mas/yr
Parallax (π)12.2595 ± 0.0538 mas[1]
Distance266 ± 1 ly
(81.6 ± 0.4 pc)
Absolute magnitude (MV)4.28[2]
Details[4]
Mass1.12±0.03 M
Radius1.35±0.03 R
Luminosity1.68±0.01 L
Surface gravity (log g)4.22±0.03 cgs
Temperature5,666±43 K
Metallicity [Fe/H]0.34±0.01[2] dex
Rotational velocity (v sin i)5.6[5] km/s
Age6.3±1.0 Gyr
Other designations
BD+19º117, HD 4203, HIP 3502, SAO 74235[6]
Database references
SIMBADdata
Exoplanet Archivedata

This object is an ordinary G-type main-sequence star with a stellar classification of G5V. It is photometrically-stable star with an inactive chromosphere, and has a much higher than normal metallicity.[3] The star is roughly 6.3 billion years old and is spinning with a projected rotational velocity of 5.6 km/s.[5] It has 12% more mass than the Sun and a 35% greater radius. HD 4203 is radiating 1.68 times the luminosity of the Sun from its photosphere at an effective temperature of 5,666 K.[4]

Planetary system

edit

Radial velocity observations of this star during 2000–2001 found a variability that suggesting an orbited sub-stellar companion, designated component 'b'.[3] Additional observations led to a refined orbital period of 432 days with a relatively high eccentricity of 0.52 for a gas giant companion.[7] The presence of a second companion was deduced from residuals in the data, then confirmed in 2014. However, the orbital elements for this companion, component 'c', are poorly constrained.[8]

The HD 4203 planetary system[7]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 1.164±0.067 MJ 2.07±0.18 431.88±0.85 0.519±0.027
c 2.17±0.52 MJ 6,700±4,500 0.24±0.13

See also

edit

Notes

edit
  1. ^ a b c d e f 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. ^ 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.
  3. ^ a b c Vogt, Steven S.; et al. (2002). "Ten Low-Mass Companions from the Keck Precision Velocity Survey". The Astrophysical Journal. 568 (1): 352–362. arXiv:astro-ph/0110378. Bibcode:2002ApJ...568..352V. doi:10.1086/338768. S2CID 2272917.
  4. ^ a b 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.
  5. ^ a b 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.
  6. ^ "HD 4203". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 4 November 2019.
  7. ^ a b Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701. S2CID 119067572.
  8. ^ Kane, Stephen R.; et al. (April 2014). "Limits on Stellar Companions to Exoplanet Host Stars with Eccentric Planets". The Astrophysical Journal. 785 (2): 10. arXiv:1401.1544. Bibcode:2014ApJ...785...93K. doi:10.1088/0004-637X/785/2/93. S2CID 2053475. 93.
edit