Kepler-89#Planetary system
{{short description|Star in the constellation Cygnus}}
{{Starbox begin
| name = Kepler-89
}}
{{Starbox observe
| epoch = J2000
| constell = Cygnus
}}
{{Starbox character
| type = main sequence
| class = F8 IV-V
}}
{{Starbox astrometry
| radial_v =
| prop_mo_ra = {{val|2.063|(10)}}
| prop_mo_dec = {{val|1.337|(11)}}
| parallax = 2.1069
| p_error = 0.0086
| absmag_v =
}}
{{Starbox detail
| mass = {{val|1.25|+0.03|-0.04}}
| radius = {{val|1.61|+0.11|-0.12}}
| temperature = 6,116
| metal_fe = {{val|−0.01|0.04}}
| luminosity =
| gravity = {{val|4.123|0.055}}
| rotational_velocity = {{val|7.33|0.32}}
| age_gyr = {{val|3.9|+0.3|-0.2}}
}}
{{Starbox catalog
| names = {{odlist | 2MASS=J19491993+4153280 | Gaia DR2=2076970047474270208 | KIC=6462863 | KOI=94}}
}}
{{Starbox reference
| Simbad = Kepler-89
| KIC = 6462863
}}
{{Starbox end}}
Kepler-89 is a star with four confirmed planets. Kepler-89 is a possible wide binary star.
Planetary system
The discovery of four planets orbiting the star was announced October 2012 by analyzing data gathered by Kepler space telescope. Follow-up radial velocity measurements confirmed the existence of Kepler-89d, indicating that Kepler-89d is slightly larger and more massive than Saturn. In October 2013, other three planets were confirmed with Kepler-89c and Kepler-89e getting reasonable mass constraints. Transit-timing variations of the outermost planet suggest that additional planets or minor bodies are present in the system.
In 2012, a partial transit of the second outermost planet by the outermost planet was reported. This was the first time a planet-planet transit in front of the star was detected. This allowed to determine the mutual inclination of the planets d and e to be 1.15°.
Stephen R. Kane did a dynamical analysis of the Kepler-89 system that demonstrated that planets c and d, although close to the 2:1 secular resonance, are not permanently in a 2:1 resonance configuration.
{{OrbitboxPlanet begin
| name = Kepler-89
| table_ref =
}}
{{OrbitboxPlanet
| exoplanet = b
| mass_earth = <10.5
| period = 3.7
| semimajor = 0.05
| eccentricity =
| inclination = 89.3
| radius = 0.13}}
{{OrbitboxPlanet
| exoplanet = c
| mass_earth = 7.3-11.8
| period = 10.4
| semimajor = 0.099
| eccentricity = <0.1
| inclination = 88.36
| radius = 0.31
}}
{{OrbitboxPlanet
| exoplanet = d
| mass = 0.33±0.034
| period = 22.3
| semimajor = 0.165
| eccentricity = <0.1
| inclination = 89.871
| radius = 0.83
}}
{{OrbitboxPlanet
| exoplanet = e
| mass_earth = 11.9-15.5
| period = 54.3
| semimajor = 0.298
| eccentricity = <0.1
| inclination = 89.76
| radius = 0.49
}}
{{Orbitbox end}}
References
{{reflist|refs=
{{Cite Gaia DR3|2076970047474270208}}
{{cite constellation|Kepler-89}}
{{cite encyclopedia|url=https://exoplanet.eu/catalog/kepler_89_b--1203/|encyclopedia=Extrasolar Planets Encyclopaedia|title=Planet Kepler-89 b|access-date=26 April 2018}}
{{cite simbad | title=Kepler-89 | access-date=2020-08-07 }}
}}
{{Stars of Cygnus}}
{{2012 in space}}
Category:Planetary systems with four confirmed planets
Category:Cygnus (constellation)