WASP-19b is an

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

, notable for possessing one of the shortest orbital periods of any known planetary body: days or approximately 18.932 hours. It has a mass close to that of

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

(1.15

Jupiter mass Jupiter mass, also called Jovian mass, is the unit of mass equal to the total mass of the planet Jupiter. This value may refer to the mass of the planet alone, or the mass of the entire Jovian system to include the moons of Jupiter. Jupiter is by ...

es), but by comparison has a much larger radius (1.31 times that of Jupiter, or 0.13

Solar radii Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: :1\,R_ = 6.957\tim ...

); making it nearly the size of a low-mass star. It orbits the star WASP-19 in the

Vela constellation Vela is a constellation in the southern sky, which contains the Vela Supercluster. Its name is Latin for the sails of a ship, and it was originally part of a larger constellation, the ship ''Argo Navis'', which was later divided into three part ...

. At the time of discovery it was the shortest period

hot Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere tem ...

discovered as planets with shorter orbital periods had a rocky, or metallic composition. A study in 2012, utilizing the

Rossiter–McLaughlin effect The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when an object moves across the face of a star. Description The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when either an eclipsing binary's secon ...

, determined the planetary orbit is well aligned with the equatorial plane of the star, misalignment equal to -15°. In 2013, secondary eclipse and orbital phases were barely observed from the data gathered with ASTEP telescope, making it the first detection of such kind through ground-based observations. This was possible due to the large size of the planet and its small semi-major axis. In 2019 the planet was observed with

TESS Tess or TESS may refer to: Music * Tess (band), a Spanish pop band active from 2000 to 2005 * TESS (musician), a UK musician Film and theatre * ''Tess'' (1979 film), a 1979 film adaptation of '' Tess of the d'Urbervilles'' * ''Tess'' (2016 film ...

and the eclipse of the planet was measured. The broad variations caused by the changing aspect of the heated face of the planet were measured. The study deduced that the dayside has a temperature of 2240 ± 40 K (1967 ± 40

°C The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The ...

) and that the planet reflects 16 ± 4 percent of the light that falls on it.The last value is relatively high compared to other planets. Despite the short orbital period, orbital decay of WASP-19b was not detected as of 2019. In August 2022, this planet and its host star were included among 20 systems to be named by the third

NameExoWorlds NameExoWorlds (also known as IAU NameExoWorlds) is the name of various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, which would later be considered for official ad ...

project.

Atmosphere

In December 2013, scientists working with the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most vers ...

reported detecting

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

in the atmosphere of the exoplanet. In September 2017, astronomers using the

Very Large Telescope The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m acro ...

at the European Southern Observatory reported the detection of

titanium oxide Titanium oxide may refer to: * Titanium dioxide (titanium(IV) oxide), TiO2 * Titanium(II) oxide (titanium monoxide), TiO, a non-stoichiometric oxide * Titanium(III) oxide (dititanium trioxide), Ti2O3 * Ti3O * Ti2O * δ-TiOx (x= 0.68–0.75) * T ...

(TiO) in WASP-19b's atmosphere. This was the first time titanium oxide had been detected in an exoplanet atmosphere. They also detected a strongly scattering

haze Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classificati ...

in the atmosphere as well as the element

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

, and additionally confirmed the presence of water. Strong haze and barely discernible titanium oxide signal were confirmed in 2021, while no sign of water or alkali metals can be found. A study using

data concluded that the atmosphere of WASP-19b is moderately efficient at transporting heat from the dayside to the nightside. Clear to cloudy hot Jupiters

References

External links

{{DEFAULTSORT:WASP-19b Exoplanets discovered by WASP Exoplanets discovered in 2009 Giant planets Hot Jupiters Transiting exoplanets Vela (constellation)