WASP-39b, officially named Bocaprins, is a "

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 temp ...

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 ...

discovered in February 2011 by the

WASP A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...

project, notable for containing a substantial amount of water in its

atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. ...

. In addition WASP-39b was the first exoplanet found to contain

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

and in its atmosphere, and likewise for

sulfur dioxide Sulfur dioxide ( IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic ...

. WASP-39b is in the constellation Virgo, and is about 700

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 101 ...

s from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...

. As part of the

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 ...

campaigns at the 100th anniversary of the

IAU The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...

, the planet was named Bocaprins, after the beach in the Arikok National Park of Aruba.

Characteristics

WASP-39b has a mass of about 0.28 times 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-thousandt ...

and a radius about 1.27 times that of Jupiter (91,000 km). It is a hot gas giant planet with a high temperature of 900 °C. The

exoplanet 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 ...

orbits very close (7 million km) to WASP-39, its host star, every 4 days. WASP-39b is also notable for having an extremely low density, near that of

WASP-17b WASP-17b is an exoplanet in the constellation Scorpius that is orbiting the star WASP-17. Its discovery was announced on 11 August 2009. It is the first planet discovered to have a retrograde orbit, meaning it orbits in a direction counter to th ...

. While WASP-17b has a density of g/cm³, WASP-39b has a slightly higher density of g/cm³.

Atmospheric composition

Hot water molecules were found in the

of WASP-39b in a 2018 study. The atmospheric transmission spectra, taken by different instruments, were inconsistent as in 2021, possibly indicating a disequilibrium atmospheric chemistry. High-fidelity spectra obtained by the

James Webb Space Telescope The James Webb Space Telescope (JWST) is a space telescope which conducts infrared astronomy. As the largest optical telescope in space, its high resolution and sensitivity allow it to view objects too old, distant, or faint for the Hubble ...

in 2022 did not confirm a disequilibrium chemistry. WASP-39b is one of the

's early release science targets.

Sulfur dioxide Sulfur dioxide ( IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic ...

was observed in this planet's atmosphere for the first time, or indeed of any planet outside of the

Solar System The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

, indicating the existence of photochemical processes in the atmosphere. WASP-39b is the first exoplanet in which

has been detected. Planetary transmission spectra taken in 2022 has indicated the atmosphere of WASP-39b is partially cloudy, and planet C/O ratio appears to be subsolar. The spectral signature of water,

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

were also detected.

WASP-39 (star)

The parent star WASP-39 is of spectral class G and is slightly smaller than the Sun. It lies in the Virgo constellation, 698

s from

. The star WASP-39 was named Malmok.

References

External links

{{Sky, 14, 29, 18.0, -, 03, 26, 40 Exoplanets discovered by WASP Exoplanets discovered in 2011 Giant planets Hot Jupiters Exoplanets with proper names

Characteristics

Atmospheric composition

WASP-39 (star)

See also

References

External links