KOI-730
Encyclopedia
KOI-730 is a star with an extrasolar
planetary system
discovered by the Kepler mission. Preliminary studies indicate that the KOI
-730 star system
consists of 4 planet
s orbit
ing the star
.
orbiting the star at approximately the same orbital distance every 9.8 days, with one permanently locked 60° behind the other in one of the two Trojan
Lagrangian point
s. The two co-orbital planets thought to be locked in mean motion resonances with the other two planets, creating an overall 6:4:4:3 resonance. This would have been the first known example of co-orbital planets.
However follow-up study of the system revealed that an alternative configuration, with the four planets having orbital periods in the ratio 8:6:4:3 is better supported by the data. This configuration does not contain co-orbital planets.
Fabrycky et al gives the radii as 1.8, 2.1, 2.8, and 2.4 Earth radii with orbital periods of 7.4, 9.8, 14.8, and 19.7 days respectively. http://scienceblogs.com/catdynamics/2011/09/exssii_more_transits.php#morehttp://exoplanet.eu/star.php?st=KOI-730
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
planetary system
Planetary system
A planetary system consists of the various non-stellar objects orbiting a star such as planets, dwarf planets , asteroids, meteoroids, comets, and cosmic dust...
discovered by the Kepler mission. Preliminary studies indicate that the KOI
Kepler Object of Interest
A Kepler Object of Interest is a star observed by the Kepler spacecraft which is suspected of hosting one or more transiting planets. KOIs come from a master list of 150,000 stars which itself is generated from the Kepler Input Catalog . A KOI shows a periodic dimming, indicative of an unseen...
-730 star system
Star system
A star system or stellar system is a small number of stars which orbit each other, bound by gravitational attraction. A large number of stars bound by gravitation is generally called a star cluster or galaxy, although, broadly speaking, they are also star systems.-Binary star systems:A stellar...
consists of 4 planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
ing the star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
.
Unconfirmed planetary system
An as-yet unconfirmed planetary system has been detected by the Kepler mission, containing four planet candidates. This system was initially believed to contain two co-orbital planetsCo-orbital configuration
In astronomy, a co-orbital configuration refers to two or more celestial objects that orbit at the same, or very similar, distance from their parent object as each other, i.e. they are in a 1:1 mean motion resonance....
orbiting the star at approximately the same orbital distance every 9.8 days, with one permanently locked 60° behind the other in one of the two Trojan
Trojan (astronomy)
In astronomy, a Trojan is a minor planet or natural satellite that shares an orbit with a larger planet or moon, but does not collide with it because it orbits around one of the two Lagrangian points of stability , and , which lie approximately 60° ahead of and behind the larger body,...
Lagrangian point
Lagrangian point
The Lagrangian points are the five positions in an orbital configuration where a small object affected only by gravity can theoretically be stationary relative to two larger objects...
s. The two co-orbital planets thought to be locked in mean motion resonances with the other two planets, creating an overall 6:4:4:3 resonance. This would have been the first known example of co-orbital planets.
However follow-up study of the system revealed that an alternative configuration, with the four planets having orbital periods in the ratio 8:6:4:3 is better supported by the data. This configuration does not contain co-orbital planets.
Fabrycky et al gives the radii as 1.8, 2.1, 2.8, and 2.4 Earth radii with orbital periods of 7.4, 9.8, 14.8, and 19.7 days respectively. http://scienceblogs.com/catdynamics/2011/09/exssii_more_transits.php#morehttp://exoplanet.eu/star.php?st=KOI-730
External links
- New Scientist, "Two planets found sharing one orbit", Marcus Chown, 18:01 24 February 2011, Issue 2801
- "Planetary System KOI-730 Exhibiting a Pair of Co-Orbital Planets" (warning: this site requires a browser with support for "WebGLWebGLWebGL is a software library that extends the capability of the JavaScript programming language to allow it to generate interactive 3D graphics within any compatible web browser...
")