WASP-121, also known as CD-38 3220, is a
magnitude 10.4
star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...
located approximately 850
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 1012 ...
s away in the
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
Puppis
Puppis is a constellation in the southern sky. Puppis, the Latin translation of "poop deck", was originally part of an over-large constellation Argo Navis (the ship of Jason and the Argonauts), which centuries after its initial description, was ...
.
WASP-121 has a
mass and
radius similar to the
Sun's.
The star, although metal-rich in terms of overall contents of heavy elements, is depleted of carbon. Carbon to oxygen molar ratio of 0.23 for WASP-121 is well below solar ratio of 0.55.
Planetary system
Its planet
WASP-121b
WASP-121b is an extrasolar planet orbiting the star WASP-121. WASP-121b is the first exoplanet found to contain water in an extrasolar planetary stratosphere (i.e., an atmospheric layer in which temperatures increase as the altitude increases ...
orbits around WASP-121 in about 1.27 days.
WASP-121b is the first
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 ...
found to contain
water in an extrasolar planetary
stratosphere
The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air ...
(i.e., an
atmospheric
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. A s ...
layer in which temperatures increase as the altitude increases).
In 2015, the
extrasolar planet WASP-121b
WASP-121b is an extrasolar planet orbiting the star WASP-121. WASP-121b is the first exoplanet found to contain water in an extrasolar planetary stratosphere (i.e., an atmospheric layer in which temperatures increase as the altitude increases ...
was discovered orbiting WASP-121 by the
transit method.
WASP-121b is a "
hot Jupiter"
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 ...
with a mass about 1.18 times
that of Jupiter and a radius about 1.81 times that of Jupiter.
The exoplanet orbits WASP-121, its host star, every 1.27 days.
Hot water molecules have been found in the
stratosphere
The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air ...
of WASP-121b.
In August 2022, this planetary system was included among 20 systems to be named by the third
NameExoWorlds project.
Gallery
PIA22565-Exoplanet-WASP121b-ComputerSimViews-20180809.jpg,
HD189733b.jpg, An artist's impression of a hot Jupiter planet
See also
*
List of exoplanet firsts
*
List of exoplanets discovered in 2015
This is a List of exoplanets discovered in 2015.
For exoplanets detected only by radial velocity, the mass value is actually a lower limit. (See Minimum mass for more information)
Specific exoplanet lists
References
{{Exoplanet
Lists of ...
*
SuperWASP
*
WASP-33b
WASP-33b is an extrasolar planet orbiting the star HD 15082. It was the first planet discovered to orbit a Delta Scuti variable star. With a semimajor axis of and a mass likely greater than Jupiter's, it belongs to the hot Jupiter class of pla ...
References
External links
SuperWASP Wide Angle Search for Planets: The Planets SuperWASP
{{DEFAULTSORT:WASP-121
Puppis
Planetary systems with one confirmed planet
Planetary transit variables
F-type main-sequence stars
J07102406-3905506
CD-38 3220
0495