Astronomers used NASA’s Hubble Space Telescope to detect dynamic weather activity, including a giant cyclone, on the uninhabitable exoplanet WASP-121 b. This discovery is crucial for studying the weather on distant planets, and was made possible by detailed observations and advanced computational models. Credits: NASA, ESA, Quentin Changeat (ESA/STScI), Mahdi Zamani (ESA/Hubble)
Stormy weather appearing in “Hot Jupiter”
of JupiterPlanet WASP-121 b is no place to call home. First, it orbits very close to a star that is brighter and hotter than the Sun.The planet is dangerously close to its star, with its upper atmosphere reaching scorching temperatures of 3,400 degrees Celsius Fahrenheit – Higher temperatures than steel blast furnaces.
A torrent of ultraviolet radiation from the host star heats the planet’s upper atmosphere, causing magnesium and iron gases to escape into space. The star’s powerful tidal forces changed the planet’s shape, making it look more like a football. By combining information from several years, hubble space telescope Using computer modeling, astronomers have found evidence of a giant cyclone swirling around the hellish planet. Cyclones repeatedly form and break due to the large temperature difference between the side facing the star and the dark night side. exoplanet.
![WASP 121 b (artist's concept)](https://scitechdaily.com/images/WASP-121-b-Artists-Concept-777x486.jpg)
This is an artist’s concept for the exoplanet WASP-121 b, also known as Tyros. The appearance of an exoplanet is based on Hubble simulation data for that object. Another team of scientists had previously reported, using Hubble observations, that heavy metals such as magnesium and iron were released from the upper atmosphere of the superhot Jovian exoplanet. Mark it as the first such detection. The exoplanet is dangerously close to its host star, orbiting about 2.6% of the distance from Earth to the Sun, and is on the verge of being torn apart by the star’s tidal forces. The powerful gravitational force changed the shape of the planet. Credits: NASA, ESA, Quentin Changeat (ESA/STScI), Mahdi Zamani (ESA/Hubble)
Hubble Space Telescope observes exoplanet’s atmosphere changing over three years
By combining observations over several years, NASAUsing the Hubble Space Telescope and computer modeling, astronomers found evidence of giant cyclones and other dynamic weather activity swirling around a hot Jupiter-sized planet 880 light-years away.
The planet, called WASP-121 b, is not habitable. But the results are an important early step in studying weather patterns on distant worlds and ultimately discovering potentially habitable exoplanets with stable long-term climates.
Over the past few decades, detailed observations of our solar system’s neighboring planets with telescopes and spacecraft have shown that their turbulent atmospheres are not static, but constantly changing, much like Earth’s weather. It has been. This variation should also apply to planets around other stars. However, actually measuring such changes requires many detailed observations and computational modeling.
Groundbreaking progress in exoplanet weather observation
To make this discovery, an international team of astronomers assembled and reprocessed Hubble observations of WASP-121 b taken in 2016, 2018, and 2019.
They discovered that the planet has a dynamic atmosphere that changes over time. Using sophisticated modeling techniques, the research team demonstrated that these dramatic temporal variations can be explained by weather patterns in the exoplanet’s atmosphere.
This visualization shows exoplanet temperature predictions for exoplanet WASP-121 b, also known as Tyros, over a 130-day period: sunrise, noon, sunset, and midnight. The bright yellow areas mark the dayside regions of the exoplanet, where temperatures are well above 2,100 Kelvin (3,320 degrees Fahrenheit). It is very close to its host star, about 2.6% of the distance from Earth to the Sun. Due to the extreme temperature difference between the day and night sides, astronomers believe that evaporated iron and other heavy metals that escape into the upper layers of the atmosphere on the day side partially fall to the lower layers, causing iron rain at night. I think it might be. Some heavy metals escape Earth’s gravity through the upper atmosphere. Credits: NASA, ESA, Quentin Changeat (ESA/STScI), Mahdi Zamani (ESA/Hubble)
The research team found that WASP-121 b’s atmosphere showed significant differences between observations. Most dramatically, the large temperature difference between the star-facing and dark side of an exoplanet can lead to repeated and destructive massive weather fronts, storms, and massive cyclones. . They also detected a clear shift between the hottest region of the exoplanet and the point on the planet closest to the star, as well as variations in the chemical composition of the exoplanet’s atmosphere (measured using spectroscopy).
The research team reached these conclusions by using computational models that help explain observed changes in exoplanet atmospheres. “The amazing detail in exoplanet atmospheric simulations allows us to accurately model the climate of superhot planets like WASP-121 b,” said co-postdoctoral researcher at the California Institute of Technology in Pasadena, California. Leader Jack Skinner explained. of this study. “Now we have made significant progress by combining observational constraints and atmospheric simulations to understand the time-varying weather of these planets.”
“This is a very interesting result as we move forward in observing weather patterns on exoplanets,” said Quentin Chengiato, one of the team’s principal investigators. european space agency Researcher at the Space Telescope Science Institute in Baltimore, Maryland. “Studying exoplanet climates is critical to understanding the complexity of exoplanet atmospheres on other worlds, especially in the search for exoplanets with habitable conditions.”
This visualization shows the weather patterns of exoplanet WASP-121 b, also known as Tyros. This video is slowed down to take a closer look at the exoplanet’s atmospheric patterns. Credits: NASA, ESA, Quentin Changeat (ESA/STScI), Mahdi Zamani (ESA/Hubble)
WASP-121 b: Case study in exoplanet atmospheres
WASP-121 b is so close to its parent star that its orbital period is only 1.27 days. This closeness means the planet is tidally locked, with the same hemisphere always facing the star, just as the moon always has the same side facing Earth. On the star-facing side of the planet, daytime temperatures approach 3,450 degrees Fahrenheit (2,150 degrees Kelvin).
The team used four sets of Hubble archive observations of WASP-121 b. The complete dataset included observations of his WASP-121 b passing in front of the star (taken in June 2016). WASP-121 b passing behind the star is also known as a secondary solar eclipse (taken in November 2016). and the brightness of WASP-121 b as a function of its phase angle with respect to the star (the change in the amount of light that Earth receives from exoplanets orbiting its parent star, similar to the phase period of the moon). These data were obtained in March 2018 and February 2019, respectively.
“The assembled dataset represents a significant amount of observation time for a single planet and is currently the only consistent set of such repeated observations,” Changeat said. Information extracted from these observations was used to infer WASP-121 b’s atmospheric chemistry, temperature, and clouds at various points in time. This resulted in exquisite images of the Earth changing over time. ”
Hubble’s unique capabilities are also evident in the extensive science program enabled through Cycle 31 observations, which began on December 1st. About two-thirds of Hubble’s time is devoted to imaging research, and the rest to spectroscopic research. , similar to that used for WASP-121, b. For more information on Cycle 31 Science, recent announcements.
Reference: “Does the atmosphere of superhot Jupiter WASP-121b change?” Written by Quentin Changeato, Jack W. Skinner, and James YK. Cho, Jonas Nettila, Ingo P. Waldman, Ahmed F. Al-Refaie, Akraine Dailek, Billy Edwards, Thomas Michal-Evans, Max Joshua, Giuseppe Morello, Nour Skaf, Angelos Tsiaras. , Olivia Vennot, Kai Hou Yip, January 2, 2023, Astrophysics > Earth and Planetary Astrophysics.
arXiv:2401.01465
The Hubble Space Telescope is an international cooperative project between NASA and ESA. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts science operations for Hubble and Webb. STScI is operated for NASA by the Association of Universities for Astronomical Research in Washington, DC.