The Kepler space telescope is a disused space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orbit. The principal investigator was William J. Borucki. After nine and a half years of operation, the telescope's reaction control system fuel was depleted, and NASA announced its retirement on October 30, 2018.
Any planet is an extremely faint light source compared to its parent star. For example, a star like the Sun is about a billion times as bright as the reflected light from any of the planets orbiting it. In addition to the intrinsic difficulty of detecting such a faint light source, the light from the parent star causes a glare that washes it out. For those reasons, very few of the exoplanets reported as of April 2014 have been observed directly, with even fewer being resolved from their host star.
Kepler-7b is one of the first five exoplanets to be confirmed by NASA's Kepler spacecraft, and was confirmed in the first 33.5 days of Kepler's science operations. It orbits a star slightly hotter and significantly larger than the Sun that is expected to soon reach the end of the main sequence. Kepler-7b is a hot Jupiter that is about half the mass of Jupiter, but is nearly 1.5 times its size; at the time of its discovery, Kepler-7b was the second most diffuse planet known, surpassed only by WASP-17b. It orbits its host star every five days at a distance of approximately 0,06 AU. Kepler-7b was announced at a meeting of the American Astronomical Society on January 4, 2010. It is the first extrasolar planet to have a crude map of cloud coverage.
Kepler-5b is one of the first five planets discovered by NASA's Kepler spacecraft. It is a Hot Jupiter that orbits a subgiant star that is more massive, larger, and more diffuse than the Sun is. Kepler-5 was first flagged as the location of a possibly transiting planet, and was reclassified as a Kepler Object of Interest until follow-up observations confirmed the planet's existence and many of its characteristics. The planet's discovery was announced at a meeting of the American Astronomical Society on January 4, 2010. The planet has approximately twice the mass of Jupiter, and is about 1.5 times larger. It is also fifteen times hotter than Jupiter. Kepler-5b orbits Kepler-5 every 3.5 days at a distance of approximately 0.051 AU.
Kepler-6b is an extrasolar planet in the orbit of the unusually metal-rich Kepler-6, a star in the field of view of the NASA-operated Kepler spacecraft, which searches for planets that cross directly in front of, or transit, their host stars. It was the third planet to be discovered by Kepler. Kepler-6 orbits its host star every three days from a distance of .046 AU. Its proximity to Kepler-6 inflated the planet, about two-thirds the mass of Jupiter, to slightly larger than Jupiter's size and greatly heated its atmosphere.
Kepler-8b is the fifth of the first five exoplanets discovered by NASA's Kepler spacecraft, which aims to discover planets in a region of the sky between the constellations Lyra and Cygnus that transit their host stars. The planet is the hottest of the five. Kepler-8b was the only planet discovered in Kepler-8's orbit, and is larger than Jupiter. It orbits its host star every 3.5 days. The planet also demonstrates the Rossiter–McLaughlin effect, where the planet's orbit affects the redshifting of the spectrum of the host star. Kepler-8b was announced to the public on January 4, 2010 at a conference in Washington, D.C. after radial velocity measurements conducted at the W.M. Keck Observatory confirmed its detection by Kepler.
An exoplanet is a planet located outside the Solar System. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such until 2016; no planet discovery has yet come from that evidence. What turned out to be the first detection of an exoplanet was published among a list of possible candidates in 1988, though not confirmed until 2003. The first confirmed detection came in 1992, with the discovery of terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. As of 1 May 2023, there are 5,366 confirmed exoplanets in 3,962 planetary systems, with 856 systems having more than one planet. This is a list of the most notable discoveries.
Kepler-10c is an exoplanet orbiting the G-type star Kepler-10, located around 608 light-years away in Draco. Its discovery was announced by Kepler in May 2011, although it had been seen as a planetary candidate since January 2011, when Kepler-10b was discovered. The team confirmed the observation using data from NASA's Spitzer Space Telescope and a technique called BLENDER that ruled out most false positives. Kepler-10c was the third transiting planet to be confirmed statistically, after Kepler-9d and Kepler-11g. The Kepler team considers the statistical method that led to the discovery of Kepler-10c as what will be necessary to confirm many planets in Kepler's field of view.
Kepler-11e is an exoplanet discovered in the orbit of the sunlike star Kepler-11. It is the fourth of six planets around Kepler-11 discovered by NASA's Kepler spacecraft. Kepler-11e was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. Kepler-11e is most likely a gas giant like Neptune, having a density that is less than that of Saturn, the least dense planet in the Solar System. Its low density can probably be attributed to a large hydrogen and helium atmosphere. Kepler-11e has a mass eight times of Earth's mass and a radius 4.5 times that of Earth. The planet orbits its star every 31 days in an ellipse that would fit within the orbit of Mercury. Kepler-11e was announced on February 2, 2011 with its five sister planets after it was confirmed by several observatories.
A Kepler object of interest (KOI) is a star observed by the Kepler space telescope that 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 (KIC). A KOI shows a periodic dimming, indicative of an unseen planet passing between the star and Earth, eclipsing part of the star. However, such an observed dimming is not a guarantee of a transiting planet, because other astronomical objects—such as an eclipsing binary in the background—can mimic a transit signal. For this reason, the majority of KOIs are as yet not confirmed transiting planet systems.
Kepler-40b, formerly known as KOI-428b, is a hot Jupiter discovered in orbit around the star Kepler-40, which is about to become a red giant. The planet was first noted as a transit event by NASA's Kepler spacecraft. The Kepler team made data collected by its satellite publicly available, including data on Kepler-40; French and Swiss astronomers used the equivalent to one night of measurements on the SOPHIE échelle spectrograph to collect all the data needed to show that a planet was producing the periodic dimming of Kepler-40. The planet, Kepler-40b, is twice the mass of Jupiter and slightly larger than it in size, making it as dense as Neptune. The planet is also nearly thirteen times hotter than Jupiter and orbits five times closer to its star than Mercury is from the Sun.
Kepler-40, formerly known as KOI-428, is an F-type star in the constellation Cygnus. Kepler-40 is known to host at least one planet, Kepler-40b. The star is approximately 1.5 times more massive than the Sun, and is over two times its size; it was, at upon its discovery, the largest yet discovered with a transiting planet in its orbit. Kepler-40 was first noted as home to a possible transiting object by the Kepler spacecraft; the data on the system was released to the public. A team of French and Swiss scientists used follow-up data to determine the existence of the Hot Jupiter planet Kepler-40b, and later had their results published in a scientific journal on January 4, 2011.
WASP-44b is a closely orbiting Jupiter-sized planet found in the orbit of the sunlike star WASP-44 by the SuperWASP program, which searches for transiting planets that cross in front of their host stars as seen from Earth. After follow-up observations using radial velocity, the planet was confirmed. Use of another telescope at the same observatory detected WASP-44 transiting its star. The planet completes an orbit around its star every two and a half days, and orbits at roughly 0.03 AU from its host star. WASP-44b's discovery was reported by the Royal Astronomical Society in May 2011.
HAT-P-32b is a planet orbiting the G-type or F-type star HAT-P-32, which is approximately 950 light years away from Earth. HAT-P-32b was first recognized as a possible planet by the planet-searching HATNet Project in 2004, although difficulties in measuring its radial velocity prevented astronomers from verifying the planet until after three years of observation. The Blendanal program helped to rule out most of the alternatives that could explain what HAT-P-32b was, leading astronomers to determine that HAT-P-32b was most likely a planet. The discovery of HAT-P-32b and of HAT-P-33b was submitted to a journal on 6 June 2011.
HAT-P-33b is a planet in the orbit of HAT-P-33, which lies 1,310 light years away from Earth. Its discovery was reported in June 2011, although it was suspected to be a planet as early as 2004. The planet is about three-fourths the mass of Jupiter, but is almost eighty percent larger than Jupiter is; this inflation has, as with the discovery of similar planets WASP-17b and HAT-P-32b, raised the question of what causes these planets to become so large.
Kepler-14 is a binary star system targeted by the Kepler spacecraft. It is host to one known planet: the Jupiter-like Kepler-14b. The star system was identified by Kepler as a possible planetary host, but when imaging revealed that Kepler-14 was a binary star system and not a single star, the confirmation process became protracted. The stars are separated by at least 280 AU, and the stars complete an orbit around a common center of mass every 2800 years. Both stars are larger than the Sun. They are of similar absolute magnitudes; however, the primary star is brighter as seen from Earth.
Kepler-39b, is a confirmed extrasolar object discovered orbiting the F-type star Kepler-39. It is eighteen times more massive than Jupiter, and is about five fourths its size. The planet orbits its host star at about 15% of the average distance between the Earth and Sun. Kepler-39b's host star was investigated by European astronomers along with three other stars, including the host star of Kepler-40b, using equipment at the Haute-Provence Observatory in France. Collection and analysis of data in late 2010 led to the confirmation of Kepler-39b. The discovery paper was published in a journal on June 6, 2011.
Kepler-12b is a hot Jupiter that orbits G-type star Kepler-12 some 900 parsecs (2,900 ly) away. The planet has an anomalously large radius that could not be explained by standard models at the time of its discovery, almost 1.7 times Jupiter's size while being 0.4 times Jupiter's mass. The planet was detected by the Kepler spacecraft, a NASA project searching for planets that transit their host stars. The discovery paper was published on September 5, 2011.
Kepler-47 is a binary star system in the constellation Cygnus located about 3,420 light-years away from Earth. The stars have three exoplanets, all of which orbit both stars at the same time, making this a circumbinary system. The first two planets announced are designated Kepler-47b, and Kepler-47c, and the third, later discovery is Kepler-47d. Kepler-47 is the first circumbinary multi-planet system discovered by the Kepler mission. The outermost of the planets is a gas giant orbiting within the habitable zone of the stars. Because most stars are binary, the discovery that multi-planet systems can form in such a system has impacted previous theories of planetary formation.
Kepler-47b is an exoplanet orbiting the binary star system Kepler-47, the innermost of three such planets discovered by NASA's Kepler spacecraft. The system, also involving two other exoplanets, is located about 3,400 light-years away.
