HD 11343#Planetary system
{{use dmy dates|date=September 2024}}
{{Short description|K-type giant star in the constellation Eridanus}}
{{Starbox begin|name=HD 11343}}
{{Starbox image
| image=
{{Location mark
|image=Eridanus IAU.svg|alt=|float=center|width=300
|label=|position=right
|mark=Red circle.svg|mark_width=8|mark_link=HD 11343
|x%=71|y%=79
}}
|caption=Location of HD 11343 (circled)
}}
{{Starbox observe
| constell = Eridanus
| ra = {{RA|01|50|06.33044}}
| dec = {{DEC|-54|27|53.8624}}
}}
{{Starbox character
| type = Red-giant branch star
}}
{{Starbox astrometry
| parallax = 6.4964
| p_error = 0.0156
| absmag_v = {{val|1.240|0.275|0.225}}{{efn|Calculated from star's luminosity.}}
}}
{{Starbox visbin
| reference=
| name=HD 11343 B
| period=
| axis_unitless=~2600 AU
| eccentricity=
| inclination=
| node=
| periastron=
| periarg=
|primary=HD 11343 A}}
{{Starbox detail
| component1 = HD 11343 A
| mass = {{val|1.17|0.28}} / {{val|2.009|0.115}}
| luminosity = {{val|25.1|5.8|5.6}}
| gravity = {{val|2.70|0.20}}
| metal_fe = {{val|-0.15|0.08}}
| temperature = {{val|4670|100}}
| rotation =
| rotational_velocity = {{val|1.3|0.9}}
| age_gyr1 =
| component2 = HD 11343 B
| radius2 = {{val|0.698|0.062|0.060}}
| mass2 = {{val|0.680|0.078|0.083}}
| gravity2 = {{val|4.58|0.11|0.09}}
| temperature2 = {{val|4351|142|113}}
}}
{{Starbox catalog
| names = {{odlist | CD=-55 412 | TIC=231019255 | GSC=08482-01124 | Gaia DR3=4912062772547406976 | TYC=8482-1124-1 | 2MASS=J01500631-5427539 | HD=11343 | HIP=8541 | SAO=232538 | CPD=-55 351 |GC=2232 |PPM=331373 }}
}}
{{Starbox reference
| Simbad = HD+11343
}}
{{Starbox end}}
HD 11343 (HIP 8541) is a wide binary system between HD 11343 A, a K-type borderline giant star, and HD 11343 B, a red dwarf companion, located in the southern constellation of Eridanus about {{convert|500|ly|pc}} distant. Two gas giant exoplanets are known to orbit the primary star.
Stellar characteristics
The HD 11343 system has an apparent magnitude of 7.88, making it too faint to be visible by the naked eye from Earth under most circumstances, but can be observed using binoculars as an orangish dot near Achernar.
The primary component, HD 11343 A, is a red-giant branch star slightly more massive than the Sun (albeit one estimate places its mass at a significantly higher 2.0 {{solar mass|link=y}}), but approximately eight times as large in radius and 25 times as luminous. It has an effective temperature of {{convert|4670|K|C F}}, corresponding to its spectral type of K2, and is slightly metal-poor, with an iron content 71% that of the Sun.
During a 2021 survey searching for binaries within data from Gaia EDR3, the star was found to be orbited by a 13th-magnitude M-dwarf, designated HD 11343 B. It is about 70% as large as the Sun both in mass and radius, is slightly cooler than the primary red giant at {{convert|4351|K|C F}}, and is situated at a separation of roughly {{convert|2600|AU|ly}} from its brighter companion.
Planetary system
In 2016, a super-Jupiter planet orbiting HD 11343 A was discovered from radial-velocity observations, alongside three other substellar companions to giant stars, namely HIP 74890 b, HIP 84056 b, and HIP 95124 b. This planet, HD 11343 b, is estimated to be slightly larger than Jupiter and has a mass of 5.7 {{Jupiter mass}}, close to the initially estimated minimum of 5.5 {{Jupiter mass}}. It revolves around its host star at a semi-major axis of {{convert|2.8|AU|km|abbr=on}}, around where the asteroid belt would lie in the Solar System, every {{convert|1585|d|yr|abbr=off}} in a mildly eccentric orbit.
Another planet, HD 11343 c, was discovered in 2022 closer to HD 11343 A, also using the radial-velocity method. The planet is reportedly a Jupiter analog, larger than the previous planet but likely considerably less massive, with a minimum mass of 0.804 {{Jupiter mass}}. It orbits its star at a distance of {{convert|0.923|AU|km|abbr=on}} every {{convert|228.5|d|yr|abbr=off}}. Due to the faintness of the astrometric signals it produces, its orbital inclination cannot be well-constrained. The discovery paper for HD 11343 c notably presents a higher mass ({{val|7.71|0.73|1.19}} {{Jupiter mass}}), semi-major axis (3.729 AU), orbital period (5.07 years), and eccentricity (0.360) for HD 11343 b.
{{OrbitboxPlanet begin
| name = HD 11343 A
}}
{{OrbitboxPlanet
| exoplanet = c
| mass = ≥0.804
| period = 228.5 {{±|3.3|3.8}}
| semimajor = 0.923 {{±|0.019|0.022}}
| eccentricity = 0.169 {{±|0.142|0.102}}
}}
{{OrbitboxPlanet
| exoplanet = b
| mass = 5.7 {{±|1.2|1.1}}
| period = 1585 {{±|27|40}}
| semimajor = 2.80 {{±|0.21|0.25}}
| eccentricity = 0.122 {{±|0.060|0.067}}
| inclination = 73.0 {{±|12.0|16.0}}
}}
{{Orbitbox end}}
Footnotes
{{noteslist}}
References
External links
- {{WikiSky|HD 11343}}
- Extrasolar Planets Encyclopaedia links: [https://exoplanet.eu/catalog/hip_8541_ab--2594/ HD 11343 b], [https://exoplanet.eu/catalog/hip_8541_ac--9309/ c]
Category:Eridanus (constellation)