HD 4203#Planetary system

{{Starbox observe

| epoch = J2000.0

| constell = Pisces

| ra = {{RA|00|44|41.2003}}

| dec = {{DEC|+20|26|56.138}}

| appmag_v = 8.70

}}

{{Starbox character

| type = subgiant

| class = G5V

| b-v = {{Val|+0.771|0.021}}

| u-b =

| variable =

}}

{{Starbox astrometry

| radial_v = {{Val|−14.20|0.09}}

| prop_mo_ra = +122.100

| prop_mo_dec = −124.204

| parallax = 12.3036

| p_error = 0.0195

| parallax_footnote =

| absmag_v = 4.28

}}

{{Starbox detail

| source =

| mass = {{Val|1.12|0.03}}

| radius = {{Val|1.35|0.03}}

| gravity = {{Val|4.22|0.03}}

| luminosity = {{Val|1.68|0.01}}

| temperature = {{Val|5666|43|fmt=commas}}

| metal_fe = {{Val|0.34|0.01}}

| age_gyr = {{Val|6.3|1.0}}

| rotational_velocity = 5.6

}}

{{Starbox catalog

| names = {{odlist | BD=+19°117 | HD=4203 | HIP=3502 | SAO=74235 }}

}}

{{Starbox reference

| Simbad = HD+4203

| NSTED = HD 4203

| EPE = HD+4203

}}

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. The distance to this object is 265 light years based on parallax, but it is drifting closer to the Sun with a radial velocity of −14 km/s.

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. The star is roughly 6.3 billion years old and is spinning with a projected rotational velocity of 5.6 km/s. 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.

Planetary system

Radial velocity observations of this star during 2000–2001 found a variability that suggesting an orbited sub-stellar companion, designated component 'b'. Additional observations led to a refined orbital period of 432 days with a relatively high eccentricity of 0.52 for a gas giant companion. 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.

{{OrbitboxPlanet begin

| table_ref =

}}

{{OrbitboxPlanet

| exoplanet = b

| mass = > {{Val|1.164|0.067}}

| period = {{Val|431.88|0.85}}

| semimajor = {{Val|2.07|0.18}}

| eccentricity = {{Val|0.519|0.027}}

}}

{{OrbitboxPlanet

| exoplanet = c

| mass = > {{Val|2.17|0.52}}

| period = {{Val|6700|4500|fmt=commas}}

| eccentricity = {{Val|0.24|0.13}}

}}

File:A top-down view of the HD 4203 system showing the orbits of the b planet and the newly discovered c planet (geminiann14002b).jpg

Notes

{{Reflist|refs=

{{cite journal |bibcode=2002PASP..114..306R |title=On the Nature of Stars with Planets |last1=Reid |first1=I. Neill |journal=Publications of the Astronomical Society of the Pacific |date=2002 |volume=114 |issue=793 |page=306 |doi=10.1086/339257 |arxiv=astro-ph/0112402 }}

{{cite journal

| title=Limits on Stellar Companions to Exoplanet Host Stars with Eccentric Planets

| display-authors=1 | last1=Kane | first1=Stephen R.

| last2=Howell | first2=Steve B. | last3=Horch | first3=Elliott P.

| last4=Feng | first4=Ying | last5=Hinkel | first5=Natalie R.

| last6=Ciardi | first6=David R. | last7=Everett | first7=Mark E.

| last8=Howard | first8=Andrew W. | last9=Wright | first9=Jason T.

| journal=The Astrophysical Journal

| doi=10.1088/0004-637X/785/2/93 | arxiv=1401.1544

| bibcode=2014ApJ...785...93K | s2cid=2053475 }}

{{cite journal

| title=Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants

| last1=Luck | first1=R. Earle

| journal=The Astronomical Journal

| bibcode=2017AJ....153...21L | arxiv=1611.02897

| doi=10.3847/1538-3881/153/1/21 | s2cid=119511744 | doi-access=free }}

{{cite journal

| title=Revising the ages of planet-hosting stars

| last1=Bonfanti | first1=A. | last2=Ortolani | first2=S.

| last3=Piotto | first3=G. | last4=Nascimbeni | first4=V.

| display-authors=1 | journal=Astronomy and Astrophysics

| year=2015 | volume=575 | at=A18

| arxiv=1411.4302 | bibcode=2015A&A...575A..18B

| doi=10.1051/0004-6361/201424951 | s2cid=54555839

}}

{{cite journal

| title=Catalog of Nearby Exoplanets

| last1=Butler | first1=R. P. | last2=Wright | first2=J. T.

| last3=Marcy | first3=G. W. | last4=Fischer | first4=D. A.

| last5=Vogt | first5=S. S. | last6=Tinney | first6=C. G.

| last7=Jones | first7=H. R. A. | last8=Carter | first8=B. D.

| last9=Johnson | first9=J. A. | display-authors=1

| journal=The Astrophysical Journal

| volume=646 | issue=1 | pages=505–522 | year=2006

| arxiv=astro-ph/0607493 | bibcode=2006ApJ...646..505B

| doi=10.1086/504701 | s2cid=119067572 }}

{{cite press release | author= | title=Limits on Binarity of Exoplanet Host Stars | url=https://noirlab.edu/public/announcements/geminiann14002/ | publisher=NOIRLab | date=2014-02-20 | access-date=2025-06-12}}

{{cite journal

| title=Ten Low-Mass Companions from the Keck Precision Velocity Survey

| last1=Vogt | first1=Steven S. | last2=Butler | first2=R. Paul

| last3=Marcy | first3=Geoffrey W. | last4=Fischer | first4=Debra A.

| last5=Pourbaix | first5=Dimitri | last6=Apps | first6=Kevin

| last7=Laughlin | first7=Gregory | display-authors=1

| journal=The Astrophysical Journal

| volume=568 | issue=1 | pages=352–362 | year=2002

| arxiv=astro-ph/0110378 | bibcode=2002ApJ...568..352V

| doi=10.1086/338768 | s2cid=2272917 }}

}}