Kepler-88 System (5.18) - Brightest star to host a transiting planet. A blue star a 385 ly away. The transiting planet had the nickname "The King of Transit Variations", a Neptune sized planet that is half as dense (sub-Saturnian?). The second is the first planet discovered by the transit variation timing technique to be confirmed by dopplar spectrometry, and is a Jovian. The planets are near the 1:2 resonance.
55 Cancri System - Copernicus is also known as Rho Cancri, 55 Cancri, Rho1 Cancri, HR 3522, Gl 324, and HD 75732. Wide binary star consisting of a sun-like primary (A, though super metal rich) and a red-dwarf secondary (B) separated by 1,100 AU, 41 light years away. Star A contains five exoplanets, the first system found with four or five planets. It has three tightly packed eccentric planets close in to the star, including planet Jannsen (e, hot Super Earth/Neptunian), Galileo (b, warm Jupiter), and Brahe (c, hot Saturn), followed by an eccentric Saturn in the habitable zone (Harriot, f) and a Jupiter analog, Lippershey (d). Planet e was heralded as the first Neptunian discovered. It was later found to be the shortest-period planet discovered (18 hours) and to transit. Its density was measured and determined to be rocky, and thus re-dubbed the first Super-Earth discovered. It was then the first super-Earth to have its light detected (by Spitzer in the infrared). The planet has about half of Neptune's mass, but is Earth-like in size and density (2.17 Earth Radius). Studies taking into account the composition of the star suggested that it was largely made of diamond, with graphite at the surface (the first diamond planet around a Sunlike star), and the first terrestrial found with fundamentally different surface composition and processes than Earth. This was later refuted when it turned out there wasn't as much carbon in the parent star as believed. Earlier studies that assumed an Earth-like composition suggested that it would be covered with an ocean of super-critical water. The brightness of the planet was found to have raised dramatically, possibly the aftermath of cloud cover due to a volcanic eruption. The brightness of the star (also closest known to transit and only known naked eye star to do so) makes it more easily studied than other hot super Earths. It was found to be dark and its sun-facing side hot enough to melt metal. It became the first super Earth to have its atmospheric composition measured (mostly hydrogen and helium with hints of hydrogen cyanide which would only dominate in a carbon-rich environment and no traces of water vapor) and temperature mapped, and the large hemispherical temperature differences suggest little atmosphere to transport heat. Planet b (one of the original 4 Hot Jupiters discovered) is the first "warm Jupiter" found to have a puffed up atmosphere and it probably at the outer limit from the star at which a planet can lose its atmosphere in this way. Its outer atmosphere skims the surface of the star, which was detected when attempting to detect an atmosphere around transiting Janssen. The strong interaction between planets Galileo and Brahe can be detected in measurements, and it took a while to find a fit that would allow them to survive over long periods of time. Harriot is a very eccentric Saturnian in the habitable zone. Planet d is a super jovian at Jupiter-like distances, which was the first found at true Jupiter distances and still the exoplanet discovered with dopplar spectrometry with the largest known semi-major axis. It was first thought to be circular, then eccentric, and then circular again. The distant outer star causes Lippershey's axis to flip on its axis every million years. Lippershey in turn causes the other planets to flip, including its star. The axis tilt of transiting planet e should be determined at some point. "Bode's law" predicts four undiscovered planets. One of the first 20 exoplanet systems allowed to be given common names by the IAU.
HD 97658 System - HD 97658 is also known as BD+26 2184, it is a nearby (68 ly) Yellow-orange star in Leo with a transiting super Earth in a torch orbit (though further out P = 9.5 d than most transiting planets). When discovered, it was the second brightest star in the sky known to have a transiting planet. It was discovered with dopplar spectrometry. Transits were later reported (leading them to think it had radius 2.9 RE and density of 1.4, giving it a possible Neptune-like extended atmosphere of H, He, and H2O), but later retracted. After expanding the search times, transits were detected at different times. The radius is 2.3 times that of Earth, coupled with a 7.9 Earth masses give a density of 3.4, and surface gravity of 1.6 Earths, suggesting a rocky core surrounded by either liquid volatiles or an extended gas envelope. A preliminary atmosphere probe found it to be featureless, possibly with clouds obscuring it atmospheric composition like in GJ 1214b, but also possibly because the atmosphere lacks hydrogen and is therefor very compact and hard to detect.
HD 209458 System - Has first discovered transiting planet which was nicknamed Osiris due to the (first detected) comet-like tail detected and the first exoplanet around a normal star to have its mass directly measured. Also the first Inflated Hot Jupiter found. The planet may be losing its outer atmosphere, or magnetism may prevent the ions from escaping. They detected water in its atmosphere (they had failed earlier), the first time this has been done for any exoplanet. 2nd Exoplanet with detected organic compounds; like HD 189733b, it has water and carbon dioxide, but it has a lot more Methane. Was one of 2 planets to have light directly taken and thus their temperatures read (over 1000K). Tracking carbon molecules with dopplar spectrometry caused it to be the first exoplanet detected to have winds, which are raging at 5,000 to 10,000 km/h. This is believed to cause hotspots to appear at terminators rather than at the star-ward facing point. Had one of the strongest water detection of the 5 exoplanets contrasted by Hubble in 2013, though still less intense than expected, probably due to dust clouds or a haze blocking its detection.
HD 189733 System - A binary star in Velpulca (the "little fox") consisting of an Orange Dwarf star A and a Red Dwarf B (discovered shortly after planet Ab found and orbiting perpendicular to that planet's orbit and later detected in x-rays) orbiting 216 AU away. Planet Ab (the first nearby Very Hot Jupiter, originally thought to be inflated, is 13% larger and more massive than Jupiter) is the nearest transiting Hot Jupiter (62.9 ly). This is the first exoplanet to have its temperature mapped and was nicknamed Bull's Eye for its hot spot that is significantly offset from the starward pole. 5 years later, it later became the first world to have its thermal emissions mapped in both longtitude and latitude, confirming the hot spot was near the equator. Fast winds are thought to make the temperature of the eternal day and night sides nearly identical, which were later measured to be 2km/s when the planet became the first to have its wind and weather patterns mapped. It is also the first exoplanet for which scattered light in the upper atmosphere has been detected and the second exoplanet with water detected and first with Methane and then Carbon Dioxide detected. It later was the first exoplanet whose gasses were detected from Earth-based telescopes. It was also found to spin up its star and magnetically interact with it, causing stellar storms. Massive X-class solar flares blast off much of the planet's atmosphere and may render it undetectable. Hubble found that its atmosphere was a uniform blue haze. Blue was detected by determining which wavelengths were blocked during a transit. It was also found to rain molten glass, sideways, with 7000 km/hr winds and 1000C. It became the first exoplanet whose transit was detected in X-Rays, which revealed it had a very large extended outer atmosphere, which is losing material rapidly. The star is much more magnetically active for its age, possibly due to the planet's presence. There is speculation that it could have large planet-wide auroras. It's already-known mass was measured using an atmospheric pressure method to test its viability. By studying sodium spectra, it was determined that it gets hotter with altitude.
HD 149026 System - Ogma (HD 149026) is a yellow sub-giant star with the first known Saturn mass transiting planet, Smertrios. Also the first planet found with a dense core, leading credence to the core-accretion theory. Sometimes called a Super-Neptune, though it is not known if its core is rocky or icy. Also the first TEP discovered smaller than Jupiter. It was revealed to be as black as coal, twice as hot as any other known exoplanet, and hotter than some stars. One of the first 20 exoplanet systems allowed to be given common names by the IAU. The star is named after a Celtic god of eloquence, writing, and great physical strength, while the planet was named after a Gallic deity of war.
HD 17156 System - Star system containing a planet discovered by dopplar spectrometry method and later found by amateurs to transit. At the time, it smashed the records for the furthest transiting planet (period of 21 d, 0.0523 to 0.26 AU) and most eccentric orbit. Its orbit was found to be well aligned with the rotation of its star. Its size has been measured better with the Hubble Telescope (3.8 MJ). A second, unconfirmed planet has also been proposed for this system.
Kepler-21 System - One of the brightest systems in Kepler's field of vision (though not quite visible to the naked eye, the nearest Kepler system with a confirmed planet), also known as HD 179070, located 352 light years away. Kepler detected a 10 Earth mass and 1.6 Earth radii hot super-Earth orbiting 10 times nearer than Mercury does the Sun. Its temperature is about 2,960F.
WASP-33 System - Aka HD 15082, this is the only known Delta Scuti variable star (kA5 hA8 mF4) known to host a planet. The star is much hotter than the Sun and 50% more massive. The planet is a retrograde inflated hot super Jupiter and is by far hottest measured exoplanet (3150C), 900C hotter than WASP-12b, and hotter than some red dwarf stars. It is one of the 6 out of 27 planets analyzed by the WASP team found to orbit backwards around its star in 2010. The planet may be responsible for the star's pulsations.
KELT-2 System - Contains the first definitive planet found by the Kilodegree Extremely Little Telescope. It is 360 ly away in Auriga. The planet is 30% larger than Jupiter and has 50% more mass. The parent star is unusually bright for one with a Hot Jupiter, and can be detected with binoculars. This allowed the planet's atmosphere to be detected during a transit. The planet orbits the larger of two stars in a binary, which is slightly bigger than the Sun.
HAT-P-2 System - Hat-P-2b (aka HD 147506b) is the most massive measured exoplanet discovered that is clearly not a Brown Dwarf and the first transiting Hot Super Planet discovered. It is the first known transiting planet with a significantly eccentric orbit (2.8 to 9.3 million miles) and experiences significant seasons. It briefly held the record of furthest out transiting planet. It takes about a day to heat up and 4-5 days to cool down. Spitzer can measure different depths with different infrared wavelengths. Its temperature was mapped out. Its daytime is as high as 2400K, while its night is 1200K. It would have winds blowing thousands of miles per hour.
HD 80606 System (8.9) - Multiple star system (also known as Struve 1341) with a planet, which had a higher period (111 days) than any other known transiting planet and highest eccentricty (Halley's comet-like, epistellar distances to almost Earth-like distance) prior to the release of Kepler data. It is the nearest transiting Super Jupiter (4 MJ, radius slightly less than 1 RJ, 190ly). Its length of day is 36 hours. Discovered in 2001, but found to transit in 2009. Planet is the first one for which changes in weather have been observed. Potassium was detected from the high wind regions of the exosphere. In 2010 it was found to be only one of the two out of all 79 known transiting exoplanetary systems that could not support a habitable Earth-like planet, since its elongated orbit would destabilize any such planets. Planet thought to be in the process of becoming a Hot Jupiter. Observations suggested that energy transferred during closest approach to star would take 10 Billion Years to cause the orbit to circularize, meaning this tidal migration method may not be the preferred one to form hot jupiters.
Kepler-410 System - A binary star a little brighter than the Sun with a planet found by Kepler. Its relative brightness (visible with high end binoculars, third brightest host star found by Kepler) makes it a suitable planet for followup. The planet is 2.5 RE and orbits once every 17.8 days. Transit timing of 15 minutes off suggests another planet in the system.