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Exoplanetary Scratchpad

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Within 50 Light Years

  • GJ 436 System (33.3 ly, Hot Neptunian) - AC+27°28217 is best known as Gliese 436. The second known red dwarf planetary system. Contains one of the first Neptunians discovered and a few potential planets. The star is about half the sun's mass. It is over 11 Billion years old and may be a part of the old disk of the Milky Way. Planet b temporarily later found to be the smallest exoplanet (about Uranus' diameter, though over 50% its mass) known to transit its host star and is currently the nearest (33 ly). Its temperature (712K) was measured to be higher than what it would be purely from radiation (520K), perhaps due to a greenhouse effect, somewhat higher than Venus. It was originally thought to have a layer of "hot ice", water solidified due to high pressures. It turned out that it was larger than thought and hot ice was not needed. It could still be a rocky super-Earth. It was later found to have a remarkably low levels of Methane and high levels of Carbon Monoxide for its 800K temperature. Possible explanations include Methane being changed into hydrocarbon polymers due to its star's ultraviolet radiation, CO being drafted upwards with winds, or observational defects. Later, due to lack of detection of chemical signatures through the backlit atmosphere, it was concluded that high altitude clouds, perhaps made of potassium chloride or zink sulphide dust, were blocking the detection. This could be the first detection of clouds of a Neptunian. An alternate theory is that the atmosphere is filled with heavy compounds, such as water, carbond dioxide, which would compress the atmosphere and make it difficult to detect. After detection of a huge comet-like tail of Hydrogen trailing and wrapping around its orbit led to the most recent theory that it lost its Hydrogen to uv radiation and was left with a Helium dominated atmosphere with plenty of CO instead of CH4. It's significant eccentricity suggests a possible neighboring planet. Planet c was announced to be the smallest known exoplanet (1.5 Earth's diameter), but was later retracted because variations in transit timing of the first planet did not occur and the proposed orbit would be unstable. It is still thought that a second planet of some kind is possible in the system. Candidate UCF-1.01 was detected by a student in the UCF's astronomy department using the Spitzer Space Telescope. It is about 2/3 Earth's diameter (smaller than all but one confirmed exoplanet), orbits around its star in 1.5 days, and at 1000F may be a lava world without an atmosphere. UCF-1.02 also may exist. Both are thought to be about 1/3 as massive as the Earth, but are too small to get their mass measured and thus too small to be confirmed with present technology.
  • Gliese 1132 System (39 ly, Venus Analog) - Nearby (39 ly) red dwarf star with a transiting Venus type planet. Was the closest known Earth-sized planet when discovered. Planet is 1.2 the size and 1.6 the mass of Earth. It orbits once every 1.6 days and expected to be a little cooler than Venus, at 500F temperatures. It is oven hot, but cooler than any other Earth sized planet known, and likely tidally locked. Likely cool enough to retain a significant atmosphere. Since it is nearby and around a dim start, it is the first earth-sized planet whose atmosphere can be studied. Much closer than Earth-sized exoplanets found in their habitable zones, so it is more easily observed. Its transit was not detected on a single pass, but over multiple passes superimposed on each other.
  • TRAPPIST-1 System (39.2 ly, 2 Venus Analogs, Mars Analog) - A very old nearby ultra-cool dwarf star (not much larger than Jupiter) 39.13 ly away with seven transiting Earth-sized planets, more than any other system, and the first such planets around such a star. First planets found by the TRAnsiting Planets and PlanetesImals Small Telescope. The planets are very compact and the gravitational interactions are significant, with resonances linking all of them, making it possible to study their mass and densities. They're named in order of distance to star. When the innermost planet b completes 8 orbits, the next planets complete 5, 3, and 2 respectively. The outermost planet (h) was predicted to have a period in a certain resonance with the other outer planets, and this was confirmed. When h orbits twice, g orbits 3 times and f 4 times. Hubble confirmed that non of the HZ planets have extended Hydrogen atmospheres. At first, the innermost two are potentially habitable and represent the easiest to study planets for biosignatures to be detected, and the third was thought to be outside the habitable zone. The first two planets (b, c) are somewhat larger than the earth at the inner edge of the habitable zones (receive the amount of energy half-way between Mercury and Venus and Venus) and orbit at 1.5 and 2.4 days. The atmospheres of the inner planets are thought to have been destroyed by the stars intense solar wind withing millions of years. Planet b and c likely have molten rock mantles due to tidal stresses, while c likely has a rocky surface with Io-like tidally induced volcanoes and a largely rocky interior. The further out planets' atmospheres could have survived for billions of years though. The next two planets (d, e) are somewhat smaller than Earth and are a little more and a little less radiated than it in the middle of the HZ. Planet d (the smallest) likely has a global ocean, while e most likely has a largely rocky interior. Studies have shown that, depending on the composition and strength of the planet's own magnetic field, the star's magnetic field could cause induction heating to occur significantly in the middle planets. This could turn the surface into magma, or at least increase volcanic activity, raising the chances of a greenhouse. The next two planets (f, g) are somewhat larger than Earth and orbit in the outer habitable zone (at Mars like distances and at the outer edge). Planet f was at first thought to be the most habitable, but now next planet out g appears to be the most habitable. The view from the fifth planet would be remarkable, with the star appearing 10 times larger than the sun does in our sky, and the other planets appearing twice the size of the moon. Planet h is the only known planet outside the habitable zone and receives about the same irradiation as Ceres does, and yet still orbits six times closer than mercury does from the sun. There was a race among astronomers using kepler data to determine h's orbit. A study on potential cometary impacts found that the outer 3 planets could have had their original atmosphere's obliterated by the impacts, but that this would also supply new volatiles for a new atmosphere, including enough water for one earth ocean mass, suggesting they would have more massive atmospheres than the other planets.
  • 55 Cancri System (40.1 ly, Hot Super Earth+) - 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.
  • GJ 1214 System (42 ly, Mini Neptune) - A red dwarf system containing the first exoplanet discovered by the MEarth project, which seeks to detect transiting Earth-like planets around nearby red dwarves, and the second transiting super-Earth. The planet is the first of a new class of planets with low mass and low density. Atmospheric observations suggest it is not a terrestrial with an outgassed (mostly Hydrogen/Helium) atmosphere, nor a Neptune-like world (Hydrogen/Methane mix). Instead it would be a new class of water worlds, with a bulk of its mass made of water. The temperature is too hot for liquid water and not thought to have a solid surface, so it could be covered with hot ice (plasma water). Its featureless spectrum (the first Super Earth atmosphere ever studied) prompted further investigation by Hubble. No chemical fingerprints were detected in its atmosphere despite high sensitivity, leading to conclusive evidence that high altitude clouds were preventing any detection (ruling out the possibility that heavier elements in the atmosphere were compressing the atmosphere, making it hard to detect, which may be the case for other planets with no detected chemicals). These are the first clouds proven around a super-Earth. It may be the coolest transiting planet detected. Its close proximity (under 50 ly) assures promising future observation.

Within 100 Light Years

  • HD 189733 System (62.9 ly, Hot Jupiter) - 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 97658 System (68.8 ly, Hot Super Earth) - 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.
  • Gliese 3470 System (100 ly, Hot Super Earth) - Star containing a transiting hot super Earth (0.036 au, 3.3 days) discovered by HARPS. The star is small, so the ratio between stellar and planet radii is large. Atmospheric analysis (the second for any super Earth) indicated that it was not covered by thick clouds. Its radius was found to be 4.3 that of Earth. Detailed observation of its atmosphere are expected to be able to tell if it was formed close to the star or further out depending on if volatiles are found. Since the atmosphere is not likely blocked by clouds, it is thought that a detailed atmospheric composition can be taken.

Within 50 Parsecs

  • HAT-P-11 System (123 ly, Super Neptune) - Star system 120 ly away in Cygnus with the second discovered transiting Super-Neptune and the least massive transiting planet known at the time. Also observed by Kepler and dubbed "Kepler 3b". Orbit unusually eccentric for a Hot Neptune (5 day period) and is inclined 103deg to its orange dwarf star's rotation. Natural radio waves may have been detected coming from the planet. Radial drifts may point to another planet. It was the first smaller planet found to have clear skies (the four previous planets studied were cloudy), which allowed its atmospheric composition to be studied, which was composed primarily of hydrogen and helium with some water (which would be over 1000F).
  • Kepler-42 System (126 ly, 3 Temperate Super Earth) - Nearby Red Dwarf Kepler star Kepler-42 is also known as KOI-961. Has three transiting planets in torch orbits smaller than the Earth, including the smallest yet measured at the time of discovery. Planets are is c (~1.9 ME, 0.72 RE), b (~2.8 ME, 0.78 RE), and d (~0.95 ME, 0.57 RE, Earth-massed but Mars-sized). The planets have not been detected with dopplar spectrometry yet, so the masses and densities aren't known. Transits were detected independently and it is very unlikely the planets are not there. Nicknamed "Planets of the Apps" after a British amateur astronomer who alerted astronomers of the system's significance. The star was compared to Barnard's Star, in that they are both nearby and old. Comparison to this well known star assisted in the system's study. The system is comparable in scope to the Jovian system, more so than any other system. Outer Space Message Center lists this as one of the targets laser messages can get sent to.
  • K2-3 System (137 ly, 3 Super Earths) - Nearby red dwarf with a three transiting super Earths found by Kepler during its repurposed mission. The first two are scorching, but the third may be in the habitable zone. The closest transiting planets found that were luke-warm. The outermost is the nearest transiting potentially habitable planet. It is the smallest, yet most massive of the three (11.1 ME and 1.6 RE), classifying it as a Mega Earth.
  • HD 209458 System (153 ly, Hot Jupiter) - 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.
  • WASP-69 System (163 ly = 50pc) - An orange dwarf containing a transiting bloated Saturn mass planet the size of Jupiter (0.26 MJup, 1.06 RJup) with a 3.8 day period. The system is estimated to be 1 BYO. X-Rays were detected in the system, possibly indicating that the planet is undergoing a mass loss 1-2 magnitudes greater than that of HD 209458b and HD 189733b.

Within 100 Parsecs

  • HIP 116454 System (55.2pc) - HIP 11654 System
  • HD 80606 System (190 ly, Eccentric Super Jupiter) - 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.
  • WASP-80 System (Hot Jupiter) - Nearby transiting hot Jupiter (0.5 MJ, 1 RJ, 4 day period). The star is in between an Orange and Red Dwarf (K7/M1, 0.59 MS). Only the second known red dwarf known to host a transiting Hot Jupiter, and much closer than the other one. Produces one of the largest transiting depths, warranting future observation. It may be orbiting perpendicular to the rotation of its star.
  • Kepler-37 System (Mini-Planet, Sub-Earth, Super Earth) - Kepler-37 is also known as KOI-245 and UGA-1785, a nickname honoring the University of Georgia and officially authorized by NASA. This was the second official nickname sponsored by NASA and the first named after a University. It was named so because the light that is visible right now came from the star in 1801, the same year the Franklin College was founded and classes began at UGA. The innermost planet b was initially the smallest yet detected by Kepler (slightly larger than the Moon) and orbits once every 13 days. A planet this small was only detectible because of the extraordinarily stability of the parent star's (25% smaller than the Sun) light output. The second planet c is 35% further out and 75% the size of the Earth. The outermost planet is twice the Earth's size and 0.2 AU. The three planets are close to 5:8:15 mean motion resonance. The star is similar to the Sun and the smallest star measured by astroseismology (3/4 the Sun).
  • HAT-P-20 System (70 pc, Hot Super Jupiter) - A relatively nearby transiting exoplanetary system. It has a superjovian which has the second highest density of known planets at the time of its discovery.
  • HD 17156 System (78.24 pc, Eccentric Super Jupiter) - 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.
  • HD 149026 System (78.9 pc, Hot Super Neptune) - 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.
  • WASP-29 System (80 pc) - Contains a transiting Hot Saturn 80 parsecs away. The planet is about the same mass as Saturn (0.24 MJ) and 79% as massive as Jupiter. This is the smallest planet found so far by the WASP survey and the exoplanet most similar in mass and radius to Saturn. It orbits an Orange Dwarf, so is relatively cool for a Hot Jupiter. There are some indications that it also has an abundance of Carbon Monoxide, much like GJ 436b.
  • HAT-P-22 System (82 pc) - Contains a transiting Hot Jupiter 82 parsecs away which is twice Jupiter's mass and about the same size.
  • WASP-8 System (87 pc) - One of the 6 out of 27 planets analysed by the WASP team found to orbit backwards around its star in 2010. In a binary star system.
  • HAT-P-17 System (90 pc) - Star 90 parsecs away containing a transiting eccentric Hot Saturn (half of Jupiter's mass) and a long period cold Jupiter.
  • WASP-10 System (90 pc) - System that contains a super Jupiter around an orange star. At first believed to be inflated, but later found to be smaller. Has a density similar to the moon. Has a candidate planet detected by the Transit Timing Variation method.
  • WASP-18 System (100 pc) - A hot F6 star that has an Inflated Very Hot Super Jupiter that is only 2.5 stellar radii from its host star. It may perish soon once it reaches its star's roche limit, but astronomers are puzzled why it hasn't already. Because it orbits much faster than its star rotates, tidal effects should be causing it to fall inwards. Further observations should reveal its rate of decay. Has the shortest period of any Hot Jupiter at the time of its discovery in 2009 (22hours). Extremely hot because of its close distance and brightness of its star, reaches 3000K. A very large planet with 70% more radius than Jupiter and 40% more mass. Very near to the Roche limit, it is expected to be elongated (football shaped). Initially thought to be slightly eccentric, this is not the case.

Within 125 Parsecs

  • Kepler-21 System (108 pc) - 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-38 System - Nearby transiting hot super Jupiter.
  • 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.
  • WASP-34 System - Nearby transiting hot Jupiter.
  • WASP-76 System - Nearby transiting hot Jupiter.
  • WASP-84 System - Nearby transiting hot Jupiter.
  • WASP-11/HAT-P-10 System (125 parsec) - Known as HAT-P-10 and WASP-11, it was detected independently by both teams. Contains a semi-Jovian that experienced the third lowest insolation (solar radiation per area) of any known transiting planets at the time.
  • WASP-59 System - Nearby transiting warm Jupiter.

Beyond 125 Parsecs

  • XO-1 System (172 pc) - Transiting hot jupiter discovered with the use of backyard telescopes. It is about the same size of Jupiter and has a very small core. 10th discovered transiting planet. Its star was the most sun-like star with transiting planets at the time. One of 5 exoplanets whose water abundance was measured by Hubble in 2013 and found to be less abundant than expected, probably due to a layer of haze or dust blocking detection..
  • WASP-19 System (250 pc) - A Very Hot Jupiter with the shortest known period (19h) for a transiting planet at the time of its discovery late in 2009 and currently has the shortest known period for a Hot Jupiter. It's mass is slightly greater than Jupiter, but its diameter is 30% greater, making it as large as some small stars. The planet appeared brighter than expected, perhaps due to a lack of Titanian and Vanadian Oxides in the upper stratosphere (perhaps at a lower level so that it doesn't act as a dark layer). Molecules were not detected, but models suggest two possibilities, either a Carbon rich planet (plenty of CO and CH4) or a Oxygen rich planet (containing plenty of CO, CO2, and H2O). The planet is only at 1.2 times the Roche limit and likely moved inwards due to interactions with a third body. One of 5 exoplanets whose water abundance was measured by Hubble in 2013 and found to be less abundant than expected, probably due to a layer of haze or dust blocking detection.
  • WASP-12 System (267 pc) - The shortest period transiting Hot Jupiter known when discovered in 2008 and the first carbon-rich planet ever found (more Carbon than Oxygen). One of the two largest known planets at 1.79 Jupiter radii. Hottest known exoplanet at time of its discovery. Planet is being ripped apart by star. It is stretched in the shape of a rugby ball and leaves a ring around its star. Huge cloud of material detected around the planet containing elements never before detected on an exoplanet. This cloud is much larger than expected, and shrouds the entire star, making it undetectable at some wavelengths. Studying this cloud could reveal magnetic properties of the stellar system. Magnesium found in this shroud supports the blow-off theory where Hydrogen escapes from the planet so quickly other material is blown off with it. Two other Hot Jupiters are known to have planetary enveloping clouds, and others as close are expected to have similar system wide clouds, but not those further away. It has much more methane than water vapor. It may produce shock waves as it plows through its star's stellar wind (the first evidence of shocks around an exoplanet, like Earth and Saturn's bowshocks), possibly produced by a strong planetary magnetic field. This could protect its atmosphere from being stripped away. It could have a diamond core and other terrestrial planets in system would have black spots on them and also be carbon based. One of 5 exoplanets whose water abundance was measured by Hubble in 2013 and found to be less abundant than expected, probably due to a layer of haze or dust blocking detection..
  • WASP-17 System (300 pc) - An F6 type star which has the first exoplanet discovered in a retrograde orbit. Also the largest known exoplanet at 1.74 RJ and 0.5 JM. Discovered by transit. It may be "flipping" its star's axis. Orbit hints at a near planetary collision in its early years. One of the 6 out of 27 planets analyzed by the WASP team found to orbit backwards around its star in 2010. It was found to be abundant in CO, depleted in water and methane. It lacks a prominent stratosphere and has efficient day-night energy circulation. 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.

System P Mass Radius Density Gravity Distance Temp Star Disc
Mercury 0.06 ME 0.38 RE 5.427 g/cm3 3.7 m/s20.38 g[5] 0.38 AU

80 K 340 K 700 K

Venus 0.81 ME 0.95 RE 5.204 g/cm3 8.87 m/s20.904 g 635K
Earth 1.00 ME 1.00 RE 5.515 g/cm3 9.78 m/s2 1.00 AU 184 K 287.2 K 331 K
Mars 0.11 ME 0.53 RE 3.9
Jupiter 317 ME 11.2 RE 1.33

95 ME

0.3 MJ

9.4 RE

0.84 MJ

Uranus 14.5 ME 4.0 RE 1.27
Neptune 17.1 ME 3.88 RE 1.6
GJ 436 System b 23.4 ME 4.08 RE 1.51 1.18g 0.028 712K M2.5 2004
55 Cancri System e 8.58 ME 2.1 RE 5.9 0.016 5373K G8V / M3.5-4V 2004
GJ 1214 System b 6.3 ME 2.7 RE 1.87 g/cm3 0.91g 0.014 3026K M4.5 2009
HD 189733 System b 1.14 MJ 1.14 RJ 0.75 21.2 m/s² 0.031 1117K K1.5V/M 2005
HD 97658 System b 6.3 ME 2.9 RE 1.4 0.080
HAT-P-11 System b 25.7 ME 5.1 RE 1.4 0.053
KOI-961 System b 2.8 ME 0.78 RE 0.012
c 1.9 ME 0.72 RE 0.006
d 0.95 ME 0.57 RE 0.015
HD 209458 System b 0.71 MJ 1.4 RJ 0.047
HD 80606 System b 3.9 MJ 0.92 RJ 0.446
HAT-P-20 System b 7.2 MJ 0.87 RJ 0.036
HD 17156 System b 3.2 MJ 1.1 RJ 0.16
HD 149026 System b 0.36 MJ 0.72 RJ 0.043
WASP-29 System b 0.24 MJ 0.79 RJ 0.046
HAT-P-22 System b 2.1 MJ 1.08 RJ 0.041
WASP-8 System b 2.2 MJ 1.03 RJ 0.080
HAT-P-17 System b 0.53 MJ 1.01 RJ 0.088
WASP-10 System b 3.06 MJ 1.08 RJ 0.037
WASP-18 System b 10.4 MJ 1.16 RJ 0.020
Kepler-21 System b 10.5 1.6 RE 0.042

See Also[]