Astronomy:HD 4203
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pisces[1] |
| Right ascension | 00h 44m 41.2003s[2] |
| Declination | +20° 26′ 56.138″[2] |
| Apparent magnitude (V) | 8.70[1] |
| Characteristics | |
| Evolutionary stage | subgiant[3][2] |
| Spectral type | G5V[4] |
| B−V color index | +0.771±0.021[1] |
| Astrometry | |
| Radial velocity (Rv) | −14.20±0.09[1] km/s |
| Proper motion (μ) | RA: +122.100[2] mas/yr Dec.: −124.204[2] mas/yr |
| Parallax (π) | 12.3036 ± 0.0195[2] mas |
| Distance | 265.1 ± 0.4 ly (81.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.28[1] |
| Details[5] | |
| Mass | 1.12±0.03 M☉ |
| Radius | 1.35±0.03 R☉ |
| Luminosity | 1.68±0.01 L☉ |
| Surface gravity (log g) | 4.22±0.03 cgs |
| Temperature | 5,666±43 K |
| Metallicity [Fe/H] | 0.34±0.01[1] dex |
| Rotational velocity (v sin i) | 5.6[6] km/s |
| Age | 6.3±1.0 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | 4203 data |
| Extrasolar Planets Encyclopaedia | data |
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.[1] The distance to this object is 265 light years based on parallax,[2] but it is drifting closer to the Sun with a radial velocity of −14 km/s.[1]
This object is an ordinary G-type subgiant star with a stellar classification of G5V. It is photometrically-stable star with an inactive chromosphere, and has a much higher than normal metallicity.[4] The star is roughly 6.3 billion years old and is spinning with a projected rotational velocity of 5.6 km/s.[6] 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.[5]
Planetary system
Radial velocity observations of this star during 2000–2001 found a variability that suggesting an orbited sub-stellar companion, designated component 'b'.[4] Additional observations led to a refined orbital period of 432 days with a relatively high eccentricity of 0.52 for a gas giant companion.[8] 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.[9]
| 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 | — | — |
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See also
Notes
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ Reid, I. Neill (2002). "On the Nature of Stars with Planets". Publications of the Astronomical Society of the Pacific 114 (793): 306. doi:10.1086/339257. Bibcode: 2002PASP..114..306R.
- ↑ 4.0 4.1 4.2 Vogt, Steven S. et al. (2002). "Ten Low-Mass Companions from the Keck Precision Velocity Survey". The Astrophysical Journal 568 (1): 352–362. doi:10.1086/338768. Bibcode: 2002ApJ...568..352V.
- ↑ 5.0 5.1 Bonfanti, A. et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics 575: A18. doi:10.1051/0004-6361/201424951. Bibcode: 2015A&A...575A..18B.
- ↑ 6.0 6.1 Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal 153 (1): 19. doi:10.3847/1538-3881/153/1/21. 21. Bibcode: 2017AJ....153...21L.
- ↑ "HD 4203". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+4203.
- ↑ 8.0 8.1 Butler, R. P. et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal 646 (1): 505–522. doi:10.1086/504701. Bibcode: 2006ApJ...646..505B.
- ↑ Kane, Stephen R. et al. (April 2014). "Limits on Stellar Companions to Exoplanet Host Stars with Eccentric Planets". The Astrophysical Journal 785 (2): 10. doi:10.1088/0004-637X/785/2/93. 93. Bibcode: 2014ApJ...785...93K.
- ↑ "Limits on Binarity of Exoplanet Host Stars" (Press release). NOIRLab. 2014-02-20. Retrieved 2025-06-12.
External links
Coordinates: 
00h 44m 41.2021s, +20° 26′ 56.138″
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