Hubble observed weather changes in the atmosphere of an exoplanet!

Even if the James Webb Space Telescope takes over HubbleHubble To push the boundaries of our knowledge of distant galaxies and exoplanets, we're not done hearing from the Hubble Telescope. Just because old archived notes are waiting for wisdom AstrophysicistsAstrophysicists To extract new information with new ideas and new data analysis techniques, and why not with helpAmnesty InternationalAmnesty International.

We see a new example today with the publication of an article that can be referred to arXiv Which comes from an international team ofAstronomy scientistsAstronomy scientists. The newly processed observations were taken with Hubble over the years 2016, 2018 and 2019 using Wide range camera 3 (WFC 3).

It concerns the exoplanet WASP-121 b which has already been the subject of several articles in recent years on Futura and whose name indicates that it was discovered within the framework of WASP (Wide angle to search for planets or “Wide Angle Planet Search”) project to search for exoplanets using the method Astrological transitAstrological transit It was performed using two identical instruments installed at two observatory sites, the Roque de los Mocachos Observatory and the South African Astronomical Observatory.

A planetary atmosphere has a spectral signature that represents its chemical composition, but also its composition in clouds and “haze.” Thanks to several techniques, it is possible to determine the physical and chemical properties of the atmosphere of an exoplanet. These techniques include: spectral transit, secondary transit or eclipse, direct spectral observation of the planet, or even observation of the planet at different phases around the star in order to measure temporal and seasonal changes. Discover exoplanets with our 9-episode web series available on our YouTube channel. Playlist proposed by CEA and the University of Paris-Saclay as part of a European research project H2020 Exoplanets-A. © CEA

Meteorology for Jupiter is very hot

Remember this is Hot JupiterHot Jupitereven very hot, rotates synchronoussynchronous About a star in the constellation SternSouthern HemisphereSouthern Hemisphere It is located about 880 light-years from Solar systemSolar system. Because it is slightly more massive and larger than Jupiter, it always presents the same face to its host star around which it orbits It rotates in orbitIt rotates in orbit In about 30 hours, which explains why it appears diurnaldiurnal It has risen to nearly 3,000 KelvinKelvin.

Hubble's observations include transits in front of and behind the star (see video above), which has been named Dilmun (In Sumerian kur.dilmun.na, Tilmon in Akkadian) in reference to a region mentioned throughout the history of ancient Mesopotamia, while WASP-121 was nicknamed Tylos, the Greek name for Bahrain, a small island nation on the Arabian Peninsula, located near the western coast of the Persian Gulf, Middle East. In fact, Tylos also refers to Dilmun.

Light emitted from Tylos has also been recorded by WFC 3 during its phases, such as phases VenusVenusin orbit around Dilmun.

Ultimately, the data collected can be compared to that generated by an atmospheric model with fluxes GasGasAnd changes in temperature and chemical composition of tylos. Then the researchers noted that they had already noticed signs of meteorological change in the areaAtmosphereAtmosphere of WASP-121B over several years.

This video shows a 130-day temperature forecast for the exoplanet Tylos at sunrise, noon, sunset, and midnight. The brighter yellow areas represent areas on the dayside of the exoplanet where the temperature rises well above 2,000 K due to its proximity to its host star, or about 2.6% of the distance between Earth and the Sun. Due to the extreme temperature difference between the day and night side, astronomers suspect that evaporated iron and other heavy metals that escape into the upper layers of the atmosphere on the day side are partially retreated to the lower layers, raining down iron on the night side. Some heavy metals also escape the planet's gravity from the upper atmosphere. © NASA, ESA, Q. Changeat et al., M. Zamani (ESA, Hubble)

Hurricanes were destroyed and originated in the atmosphere of an exoplanet

One of the lead researchers on the team, Quentin Changateresearcher inEuropean Space AgencyEuropean Space Agency in Space Telescope Science Institutespecified in a press release from NASANASA in this subject : ” Our dataset represents a DurationDuration An important observation for a single planet, and currently the only consistent set of repeated observations of this type. The information we extracted from these observations was used to characterize (conclude chemistrychemistryAnd temperature and cloudsclouds) of the atmosphere of the planet WASP-121 b at different times. This gave us a wonderful picture of the planet, as it changes over time. “.

The press release also explains that “ The models indicated that their results could be explained by quasi-periodic weather conditions, in particular TornadoesTornadoes Masses are repeatedly created and destroyed due to the enormous temperature difference between the star-facing side and the dark side of the exoplanet. This result represents a major advance in the potential observation of atmospheric conditions on exoplanets “.

Quentin Changat adds: “ there Weather reportWeather report On Earth it is responsible for many aspects of our lives and, indeed, the long-term stability of the world climateclimate The influence of the Earth and its weather is likely how life emerged in the first place. Studying exoplanetary weather is essential to understanding the complexity of exoplanetary atmospheres, especially in our search for exoplanets with habitable conditions. »

All this is still just the beginning and Hubble as well as Webb will allow us to go further in the field of comparative planetary science.