Artist's impression of "roaster" extrasolar planet HD 209458b (Osiris).

Artist's impression of a cooler hot Jupiter, though still glowing red with its own heat

Hot Jupiters (also called roasters, epistellar jovians, pegasids or pegasean planets) are a class of extrasolar planets whose mass is close to or exceeds that of Jupiter (1.9 × 10²⁷ kg), but unlike in our own solar system, where Jupiter orbits at 5 AU, the planets referred to as hot Jupiters orbit within approximately 0.05 AU of their parent stars, about one eighth the distance that Mercury orbits the Sun. Image File history File links Question_book-3. ... Download high resolution version (1305x1865, 593 KB)Artists impression of the evaporating planet Osiris. ... Download high resolution version (1305x1865, 593 KB)Artists impression of the evaporating planet Osiris. ... HD 209458b is an extrasolar planet that orbits the Sun-like star HD 209458 in the constellation Pegasus, some 150 light years from Earths solar system. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... An extrasolar planet, or exoplanet, is a planet beyond the Solar System. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... This article is about the Solar System. ... The astronomical unit (AU or au or a. ... Two bodies with a slight difference in mass orbiting around a common barycenter. ... This article is about the planet. ... Sol redirects here. ...

Hot Jupiters have some common characteristics:

1. They have a much greater chance of transiting their star as seen from a further outlying point than planets of the same mass in larger orbits.
2. Due to high levels of insolation they are of a lower density than they would otherwise be. This has implications for radius determination, because due to limb darkening of the planet against its background star during a transit, the planet's ingress and egress boundaries are harder to determine.
3. They are all thought to have migrated to their present positions because there would not have been enough material so close to the star for a planet of that mass to have formed in situ. It might also be possible that the planets could have been formed from material ejected from the very sun about which the planet orbits because of a previous giant impact into the sun by another, larger planet.#They all have low eccentricities. This is because their orbits have been circularised, or are being circularised, by the process of libration. This also causes the planet to synchronise its rotation and orbital periods, so it always presents the same face to its parent star - the planet becomes tidally locked to the star.

Hot Jupiters are the easiest extrasolar planets to detect via the radial velocity method, because the oscillations they induce in their parent stars' motion are relatively large and rapid, compared to other known types of planets. 2003 Transit of Mercury The term transit or astronomical transit has two meanings in astronomy: A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, as seen by an observer at some particular vantage point. ... Not to be confused with insulation. ... For other uses, see Density (disambiguation). ... The limb darkened Sun - An image of the Sun in visible light showing the limb darkening effect as a drop in intensity towards the edge or limb of the solar disk. ... Planetary migration is the act of a stellar satellite altering its orbital parameters, especially semi-major axis, through various means during its lifetime. ... In situ is a Latin phrase meaning in the place. ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... Not to be confused with Liberation. ... Tidal locking makes one side of an astronomical body always face another, like the Moon facing the Earth. ... Radial velocity is the velocity of an object in the direction of the line of sight. ...

After hot Jupiters get their atmospheres stripped away, their cores may become chthonian planets. A Chthonian planet (sometimes misspelled Cthonian), is a gas giant with its hydrogen and helium atmosphere stripped away due to its closeness to its star. ...

Hot Jupiters (along left edge, including red dots) discovered up to and including 31 August 2004. Courtesy NASA/JPL-Caltech.

Download high resolution version (1382x2161, 1149 KB)Taken from the JPL publication Precursor Science for the Terrestrial Planet Finder edited by P.R. Lawson, S.C. Unwin, and C.A. Beichman (JPL Pub 04-014, page 21, fig. ... Download high resolution version (1382x2161, 1149 KB)Taken from the JPL publication Precursor Science for the Terrestrial Planet Finder edited by P.R. Lawson, S.C. Unwin, and C.A. Beichman (JPL Pub 04-014, page 21, fig. ...

Terrestrial planets in systems with hot Jupiters

Simulations have shown that the migration of a Jupiter-sized planet though the inner protoplanetary disk (the region between 5 and 0.1 AU from the star) is not as destructive as one might assume. More than 60% of the solid disk materials in that region are scattered outward, including planetesimals and protoplanets, allowing the planet-forming disk to reform in the gas giant's wake.^[1] In the simulation, planets up to 2 Earth masses were able to form in the habitable zone after the hot Jupiter pass through and its orbit stabilized at 0.1 AU. Due to the mixing of inner solar system material with outer solar system material from beyond the "snow line", simulations indicated that the terrestrial planets that formed after a hot Jupiter's passage would be particularly water-rich.^[1] Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks. ... Protoplanets are moon-sized planet embryos within protoplanetary discs. ...

References

arXiv (pronounced archive, as if the X were the Greek letter χ) is an archive for electronic preprints of scientific papers in the fields of physics, mathematics, computer science and quantitative biology which can be accessed via the Internet. ...

External links

• Inside Exoplanets: Motley Crew of Worlds Share Common Thread
• NASA: Global temparature map of a exoplanet