Hot Jupiters

Hot Jupiters are also known as Roasters, Epistellar Jovians, Pegasids, or Pegasian planets. Some definitions are that they are Jupiter-sized planets with a period of about 3 days. They are planets as massive as Jupiter, but orbit extremely close to their stars. These are the easiest to detect using the Dopplar Spectrometry method and transiting method. The first discovered was 51 Pegasi, nicknamed Bellerophon. There are many sub-varieties. Many are thought to be tidally locked to their star, though not all. Some have super fast winds that transport heat from the day side to the dark side, meaning their temperatures are similar on both sides. Others have no winds and have much hotter day sides than night sides. They are thought to have formed far beyond the frost line and then migrated inward. Some are extra "puffy", with the largest being twice the diameter of Jupiter. Some interact magnetically with their stars, causing x-ray activity, star spots, or massive solar flares. Some have extended atmospheres. Some are losing mass and form a tail or ring around their system. They usually orbit in very circular paths, but are often at high inclination to the star's orbit, or even retrograde. They are among some of the best studied planets. Transits can often detect their atmospheres, measure their temperatures, color, and albedo, and detect molecules in their atmosphere. Classification is based on orbital period and mass, not other properties such as temperature. Though rare, Hot Jupiters around Red Dwarves can be much lower in temperature. Some are enveloped by their stars as they get older.

Hot Jupiters Web Pages[]

Wikipedia

Sub-Types[]

Types based on mass, densities, and orbital periods[]

Normal Hot Jupiters - Hot Jupiters that are not Very Hot Jupiters, Hot Saturns, or Hot Super Jupiters.
Very Hot Jupiters - Hot Jupiters with a period of about 1.5 days, sometimes described as having a period of less than 2 days. There is a tendency for very hot jupiters to be more massive than normal hot jupiter (about twice Jupiter's mass), possibly because smaller Jupiters would not survive that close in to their stars.
Inflated Hot Jupiters - Hot Jupiters that are larger than theoretical models predict for their temperature and mass. Also called "puffed up", "puffy", or "bloated" planets. May be larger than Hot Saturns (similar density to Saturn) or also be Hot Saturns.
Hot Saturns - Hot Jupiters that are often inflated to well over Jupiter's size and thus have densities near that of Saturn.
Hot Super Jupiters - Hot Jupiters with more mass than Jupiter.
See also Warm Jupiters - Jupiter-sized planets warmer than the Earth, but cooler than Hot Jupiters. Some definition give them as Jupiter sized planets with orbital periods of about 2 weeks. The first discovered was 55 Cancri b. Some of these planets have extended atmospheres that can extend to their stars. These planets may be analogous to "Clarified Giants", or Jovians that have no clouds and thus appear sky blue.

Misc Types[]

Types based on temperature distribution[]

Uniform Hot Jupiters - Hot Jupiters that feature super-sonic winds that transport heat from the eternal day side to the eternal night side so that temperature is fairly uniform between the day side and the night side. 51 Pegasi b, HD 179949 b, and HD 209458 b are the first confirmed cases.
Fire and Ice Hot Jupiters - Hot Jupiters whose day sides and night sides show stark contrast in temperatures. These planets lack the supersonic winds that cause some Hot Jupiters to have uniform temperatures. Heat may somehow be shed to outer space quicker than it can be transported to the other side of the star. Upsilon Andromedae b is the first confirmed case.

Types based on physical interaction with star or other planets[]

X-Ray Inducing Hot Jupiters - Hot Jupiters that interact magnetically with their stars and cause them to emit X-Rays. Sometimes this is in the form of an X-Class stellar flare. HD 179949b is the first known case.
Magnetically Interactive Hot Jupiters - Hot Jupiters known to magnetically interact with their host stars. The magnetic fields of the stars and planets interact, which may cause increased starspots, increased stellar flare activity (often engulfing the planet), X-Ray emissions, and bright spots on the star.

Types based on rotational interaction with their star[]

Tidally Locked Hot Jupiters - Most Hot Jupiters are assumed to be tidally locked to this star, but this is not always the case. This can cause one side to experience eternal night and the other eternal day, with an eternal twilight zone in between. Some such planets are much hotter on the day side than on the night side. Supersonic winds can distribute heat evenly throughout the planet, causing the temperatures to be the same on both sides.
Non-Tidally Locked Hot Jupiters - Hot Jupiters not tidally locked to their host stars. HD 179949 is one example.
Doubly Tidally Locked Hot Jupiters - A Hot Jupiter that is tidally locked with its star and that also tidally locks its star's rotation. The length of day of the star, orbit period of the planet, and length of day of the planet are all the same. Tau Bootis b was the first known case of this.

Types based on escaped materials[]

Evaporating Hot Jupiters

Types based on orbit shapes[]

Circular Hot Jupiters
Eccentric Hot Jupiters
Aligned Hot Jupiters
Inclined Hot Jupiters
Retrograde Hot Jupiters
Inclined Hot Jupiters

Types based on albedos[]

Hot Jupiters In the News[]

Earth Sized Planets Not Found in Kepler Data for Systems with Hot Jupiters (May 2012)[]

No companion planets found that are 2/3 to 5 times Earth's mass in systems that harbor Hot Jupiters (about 3 day periods), while such companions are found in systems with Warm Jupiters and Hot Neptunians.

http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=205

Evaporating Companion Star May Explain Misaligned Hot Jupiter Tilt (Nov 2012)[]

http://arstechnica.com/science/2012/11/misaligned-planets-left-behind-when-a-parent-abandons-them/

Systems with Hot Jupiters May Have Mini Oort Clouds (Nov 2012)[]

http://www.skyandtelescope.com/news/Making-Mini-Oort-Clouds-in-Extrasolar-Systems-179827191.html

Example Systems[]

First Hot Jupiters Discovered With Dopplar Spectrometry[]

51 Pegasi System (1995) - The star called 51 Pegasus is now known as Helvetios. Contains the first exo-planet around a normal star discovered and the first "Hot Jupiter" found, which is nicknamed "Bellerophon", and now called Dimidium. Star is about 50 ly located in the square of Pegasus, a G5 star somewhat larger and more massive than the Sun. The planet's discovery was incompatible with planetary system formation models, so they were tweaked to allow for planetary migration. It was also initially thought to be an anomaly or the stripped down core of a brown dwarf. Found to have supersonic winds that caused the eternal night-side hemisphere to be as hot as the day-side one. During its 20th anniversary, this planet became the first one's whose reflected visible light was detected. The technique involved looking at a star's visible spectrum, and then detecting a faint reflection of this spectra. Its actual mass (0.46 MJ) and inclination (9deg) were obtained as a result. The planet seems to have a larger radius and bright surface, rather typical for hot jupiters. One of the first 20 exoplanet systems allowed to be given common names by the IAU. The star's name is Latin for a Celtic tribe that lived in Switzerland (the place where its planet was discovered) during the middle ages. The planet's name is Latin for "half" due to the fact its minimum mass is half as massive as Jupiter's.
Tau Bootis System (1996) - Contains one of the first four discovered Hot Jupiters, which was one of the largest, hottest, closest in (P = 3.3d, a = 0.05) of the earlier discovered ones and the closest known at the time and is today one of the brightest planets known. It was immediately recognized to have tidally locked its star's rotation period. The star (also known as HR 5185) is nearby (50 ly), 1.5 times as massive as the sun. The planet does not transit its star, but is one of the brightest planets known. Several attempts to detect light were declared, but then refuted. In one such attempt by British astronomers, it was nicknamed the "Millenium Planet", and light was thought to have been detected (thought to be a first) by subtracting its star's light, giving an inclination of 29deg, mass of 8 MJ, and size of 1.8 RJ, and blue-green color. NASA's Spitzers later was thought to have detected it (again, a believed first, considering visually detected ones were planetary "candidates"). It was finally detected later by observing CO lines produced by reflected light through its atmosphere, yielding a mass of 6 MJ and inclination of 44F. Water was later also detected in its atmosphere in the near infra-red, the first for any non-transiting exo-planet. The temperature was unexpectedly found to be cooler at the upper levels, unlike many other hot Jupiters (strong ultraviolet radiation are thought to destroy the compounds responsible for creating thermal inversions in this case). The star was the first to have its magnetosphere detected (which envelopes the planet) and also the first known to magnetically flip like the Sun (flips once every Earth year, vs the Sun's 11 years). One of the first 20 exoplanet systems allowed to be given common names by the IAU, but the only one whose chosen name was rejected because it did not conform to IAU's naming standards.
Upsilon Andromedae System (1996) - Titawin (Upsilon Andromeadae) is a nearby (44 ly) multi-star system which is the first multiplanet system found around a main sequence star or a multi-star system. The main star around which the planets orbit is a yellow-white star somewhat younger than the sun and its companion is a red dwarf in a wide orbit. It is one of the most well studied non-transiting star systems. Roaster Saffar (b, 0.05 au, 0.62 MJ, e=0.013, and the nearest true Hot Jupiter to Earth) is nicknamed the Fire and Ice Planet because it is hot on one side and cold on the other. The hottest parts of the planet are near the trailing side terminator at the equator, due to high velocity winds transporting heat to the night side. This is 80deg offset from the starward pole and a much greater offset than other observed hot Jupiters. This threw astronomers off and caused them to doubt the wind-theory, though later observations of other planets have shown that winds indeed can travel fast enough to cause this. Stability studies and observations suggest its diameter is 1.8 DJ, rather large for a planet its age. The middle planets Samh (c, 0.83 au, 1.8 MJ, initially thought to possibly be a brown dwarf star, e=0.224) and Majriti (d, 2.5 au, 10.2 MJ, e=0.26) have had their inclinations and masses determined with astrometry, the first determination of relative inclinations of exoplanets. They are very eccentric and highly inclined to each other (30 deg). Planet scattering was thought to be a source until the outermost planet was discovered. This is planet e (5.2 au, 1.05 MJ, e = 0.005), which is the most Jupiter-like exoplanet known, and is in 3:1 resonance with planet d. Planet c is in the habitable zone, though any habitable moons would see drastic temperature swings. The star appears to have no Kuiper-belt like disc, perhaps due to its companion star sweeping away this material. One of the first 20 exoplanet systems allowed to be given common names by the IAU. The star is named after an important city in Morocco that bridged the Spanish and Arab worlds. The planets are named after famous Andalusian astronomers.
HD 187123 System (1998) - Solar twin system containing one of the earlier discovered Hot Jupiters (similar to 51 Peg b) and that had early indications of an outer planet. The confirmation of this massive distant eccentric jovian was announced at the May 2007 AAS media briefing, along with 27 other exoplanets. No transits have been detected for this planet.

HD 217107 System (1998) - Contains the first discovered moderately eccentric Hot Jupiter. Its outer planet was suspected when the inner one was discovered due to its eccentricity (0.13) and confirmed with four other new multiplanet systems in 2005. The Outer planet c is highly eccentric and skirts the outer edge of the habitable zone.
HD 130322 System (1999) - A cloudless blue jovian around an orange dwarf star discovered by the Coralie survey. Called a Hot Jupiter by its discoverers due to its low orbital period, it could also be thought of as a Warm Jupiter due to its relatively cooler temperature.
HD 75289 System (1999) - A nearby yellow dwarf star (94.4 ly) with a Red Dwarf about 620 AU. 0.4 Jupiter massed planet Ab was predicted to be a Cloudy Hot Jupiter by Extrasolar Visions website, which have bright silicate clouds above its dark sodium haze. However, by studying its star's light, it has been concluded that the planet must have a very low albedo for a Hot Jupiter, otherwise the planet's reflected light would have been detected. Star B would only appear as bright as Saturn does from the planet.

First Transiting Hot Jupiters[]

HD 209458 System (1999) - 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.
OGLE-TR-56 System (2002) - Contains first planet discovered by transit and later confirmed by Dopplar Spectroscopy (rather than the other way around). The first OGLE planet confirmed with the Dopplar method. It is 6000 ly away, 10 times as far as any previous known planet, in a different arm of the galaxy. Also the first Very Hot Jupiter and the first non-inflated Hot Jupiter discovered. It may meet its doom in less than a million years. Planet has one of the first two ground-detected atmospheres. Has an atmosphere hotter than any other measured so far. Unlike other hot Jupiters observed, it is way too hot for clouds of silicon or iron to form which would keep it dark.

OGLE-TR-113 System (2004) - A binary orange dwarf star 1800 ly away in a crowded star field in Carina. It contains the second discovered Very Hot Jupiter (34 hours, 0.023 au, 1.3 MJ) and one of the first discovered transiting planets. At one time it was the only known transiting Hot Jupiter with a surface gravity greater than Jupiter's. Between 2002 and 2009, its transit times were found to shorten by 60 ms per earth year. This indicates that it is slowly spiraling towards its sun, the first exoplanet found to be doing this, and may get ripped apart by its star in 1.4 million years, when its period is reduced to 10.8 hours. An alternate explanation may be that an unseen planetary companion is causing the timing differences.
OGLE-TR-111 System (2004) - A yellow dwarf with a Hot Jupiter about half Jupiter's mass. Has the first OGLE-detected transiting "normal" Hot Jupiter (the others had unusually short periods). Data suggests the presence of a second planet, which, if confirmed, would make this the first system with more than one transiting planet.
OGLE-TR-132 System (2004) - Has the third discovered Very Hot Jupiter, validating the believability of the first one found. Transit timing analysis showed no variation, placing limits on further out planets.
OGLE-TR-10 System (2004) - Contains a bloated Hot Jupiter expected to be losing its atmosphere. Noted for its similarity to the first transiting exoplanet. Thought to not be so bloated, but then confirmed to really be bloated. Found to have the lowest measured surface gravity of any of the transiting exoplanets, considerably less than Earth. 5th confirmed OGLE planet. The first star observed to experience a stellar flare during the transit of one of its planets. The star is suggested to be active and have a high x-ray luminosity.
TrES-1 System (2005) - Contains the first transiting exoplanet discovered with the TrES amateur equipment and second transiting exoplanet close enough to have its atmosphere studied. It is the first Hot Jupiter that had the expected radius. Was the one of the first two exoplanets to have its light separated from its host star. Has a cloud or torus of particles around it. Tidal heating is predicted due to its eccentric orbit, but this has not seem to have inflated its radius.
HD 149026 System (2005) - 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 189733 System (2005) - 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.

Hot Jupiters Within 50 Light Years[]

Upsilon Andromedae System (44 ly) - See First Hot Jupiters Discovered With Dopplar Spectrometry
51 Pegasi System (48 ly) - See First Hot Jupiters Discovered With Dopplar Spectrometry

Transiting Hot Jupiters Within 100 Parsecs[]

HD 189733 System (19 pc) - See First Transiting Hot Jupiters
HD 209458 System (47 pc) - See First Transiting Hot Jupiters
HAT-P-20 System (70 pc) - 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 149026 System (79 pc) - See First Transiting Hot Jupiters
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.
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.
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.

Shortest Period Hot Jupiters[]

See Very Hot Jupiters

PSR 1719-14 System (2 hours) - A millisecond pulsar containing a planet composed of a heavy elements such as Carbon and Oxygen and likely has a diamond-like crystalline structure. The planet is the compressed remnants of a white dwarf star with 99% of its massed ripped away. Orbits only once every 2 hours (closer than the radius of the Sun).
Gliese 163 System (0.6 days) - A nearby red dwarf system 50 light years containing three planets, including one potentially habitable one. The innermost planet b is a Hot Jovian with a third of Jupiter's mass (have some data discrepancy, Extrasolar Planet Encyclopedia says 0.35 Jupiter Mass, 0.6 day period, Wikipedia says 9 days. The latter is more likely since it's not acknowledged as a Hot Jupiter around a Red Dwarf.). The potentially habitable planet c is 7 Earth masses large and receives 30-40% more radiation than the Earth does, on the inner edge of the habitability zone. It is thought to be unlikely that any runaway greenhouse gas would heat it up beyond habitability. It is the fifth most similar exoplanet of the six known potentially habitable exoplanets known at the time of its discovery. Likely too hot for most organisms, but some extremophiles may flourish on it. Its composition is unknown, but it is thought to be a mixture of rock and ice. There's a possibility of an outermost planet with 20 times Earth's mass much further out with a period of 669 days.
WASP-19 System (0.8 days) - 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-43 System (0.8 days) - Orange dwarf star with a Very Hot Jupiter 260ly away. The star was the smallest mass star known to have a Hot Jupiter at the time of the planet's discovery. The planet is currently the Hot Jupiter (Jupiter size but twice as massive) orbiting the closest to its star (though not the smallest period, 19 hours) when discovered. The planet is relatively dense, with a mass of 1.78 Jupiter, but only 93% of its radius. The tidally locked day side is 3000F, while it's night is 1000F. The most detailed weather map was obtained for this planet, thanks to the first observations of three whole periods of any planets. One mapped the thermal properties of different longitudes, and the other its water distribution. The planet reflects very little sunlight, indicative of no water clouds in the atmosphere.
WASP-18 System (1 day) - 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.
WASP-12 System (1 day) - 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..
OGLE-TR-56 System (1.2 day) - Contains first planet discovered by transit and later confirmed by Dopplar Spectroscopy (rather than the other way around). The first OGLE planet confirmed with the Dopplar method. It is 6000 ly away, 10 times as far as any previous known planet, in a different arm of the galaxy. Also the first Very Hot Jupiter and the first non-inflated Hot Jupiter discovered. It may meet its doom in less than a million years. Planet has one of the first two ground-detected atmospheres. Has an atmosphere hotter than any other measured so far. Unlike other hot Jupiters observed, it is way too hot for clouds of silicon or iron to form which would keep it dark.

HAT-P-23 System (1.2 day) - A yellow dwarf star system containing very hot super Jupiter.
WASP-33 System (1.2 day) - 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.
TrES-3 System (1.3 day) - Has planet TrES-3, the most massive transiting Very Hot Jupiter planet. Planet has one of the first two ground-detected atmospheres. A large ground-based telescope method of observation was pioneered on this planet.

By Stellar Flux[]

WASP-33 System (8573, VHJ)- 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.
WASP-12 System (6872, VHJ) - 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-18 System (5434, VHJ) - 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.
OGLE2-TR-L9 System (5115, HJ) - First planet discovered around a rapidly rotating hot star and the hottest star with planets. Was detected by students while testing a method for investigating light fluctuations in the OGLE database. An inflated hot super Jupiter. Nicknamed "ReMeFra-1" for its discoverers.
HIP 13044 System (4073, WJ, no transit) - The first found planetary system that originated from another galaxy and lies 2000 ly away in the constellation Fornax. The star is slightly less massive than the sun and is near the end of its life. It has already passed through the Red Giant phase, but may soon envelope its epistellar giant planet during its next expansion. This is the only star at such a stage known to have a planet and may have swallowed smaller planets. Planet b must have originated further away from the star in order to have survived the Red Giant phase of the star and was then pulled inward to its present location. The star is from the Helmi stream, which is a remnant of a dwarf galaxy enveloped by the Milky Way 6 to 9 Billion years ago. It is the first planet discovered around a star that is both very old and very metal poor, the poorest star known so far with a planet, showing that planets could form around such stars, probably due to gravitational collapse rather than core accretion. It may be made completely of Hydrogen and Helium with no core. It was discovered just prior to the 500th exoplanet.
WASP-78 System (3848, HJ) - WASP-78 System
WASP-79 System (3494, HJ) - WASP-79 System
HAT-P-7 System (3438, HJ) - F8 star also known as GSC 03547-01402 containing a transiting Hot Jupiter and an outer Jovian and a further out stellar companion. Transiting planet was used as a test for the Kepler mission (dubbed Kepler 2), which was able to detect the planet's occulation, as well as evidence of phases. Very little of its heat is transported to its night side, with its hottest spot being 1,300 F hotter than its coldest spot. Extremely strong easterly winds are produced as a result, but the planet's magnetic field has been shown to disrupt the direction of these winds at some times. This is because the high temperatures strip electrons from the atmospheric atoms of lithium, sodium, and potassium, making them positively charged, which follow the magnetic field lines. The stronger field lines may completely reverse the direction of the winds. Variation in brightness has been thought to be due to clouds of corundum (which emeralds and sapphires are made of) being blown into the dayside by the winds and then dissipating in the intense heat. Its atmosphere could be made up of exotic gases like Titanium Oxide. The Hubble Space Telescope made its 1,000,000th science observation on this planet in the attempt to detect water in its atmosphere. The planet may "lift" its stars surface up gravitationally, reducing its temperature a fraction of a degree in a darkened spot that lags a few hours behind the planet. It was found by a Japanese team to be orbiting backwards only a day after the first retrograde exoplanet WASP-17b was announced. The Japanese team inspected two stars nearby, measured their proper motions, and found that one of them was a member of the system. They also confirmed an outer radial velocity detected Jovian between the planet c and companion star B. Star B is suspected of tilting planet c's orbit, which in turn affected planet b's orbit and caused it to orbit backwards.
WASP-19 System (3169, VHJ) - 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-71 System (3016, HJ) - WASP-71 System

Other Hot Jupiters in the News[]

KOI-254 System - The first Red Dwarf confirmed to have a true Hot Jupiter. This challenges current planetary formation theories.