The first study with exoplanet satellite data describes the most extreme planets in the universe

CHEPS keeps its promise: Observations with the Space Telescope have uncovered details of Exoplanet WASP-189B – one of the most extreme planets. Chipes is a joint mission by the European Space Agency (ESA) and Switzerland, in collaboration with the University of Geneva and the University of Bern.

Eight months after the space telescope CHEOPS began its mission, the first scientific publication using CHEOPS data has been issued. The EOPS is the first known ESA mission to orbit known exoplanets, orbiting stars outside the solar system. Exoplanets were first discovered in 1995 by two Swiss astronomers, Michel Meyer and Didier Klose, who were awarded the Nobel Prize for this discovery last year. CHEPS was developed as part of a partnership between ESA and Switzerland. A union of more than 100 scientists and engineers from 11 European states, led by the University of Bern and ESA, has been involved in the construction of the satellite for five years. CEOPS’s Science Management Center is located at the University of Geneva Observatory.

Using data from Chappops, scientists have recently conducted a detailed study of Exoplanet WASP-189B. The results have just been accepted for publication in the journal Astronomy and Astrophysics. “These observations show that CHEPS fully meets the high expectations regarding its performance,” said Willie Benz, professor of astrophysics at the University of Bern and head of the CEOEPS consortium.

The most extreme planets in the universe

WASP-189B, the target of Cheoeps observations, is an exoplanet orbiting the constellation HD 133112, one of the well-known planets with a planetary system. “The WASP-189 system is 322 light-years away and located in Libra (scales of weight),” explains Monica Lendl, lead author of the study at the University of Geneva and a member of the National Center for Competitiveness in Research Planets. .

“WASP-189B is particularly interesting because it is a gas giant that orbits very close to its host star. It takes less than three days to circle its star, and the Earth is 20 times closer to the star than the Sun.” Says Monica Lendl. This planet is 1.5 times larger than Jupiter, the largest planet in the Solar System.

Monica Lendl further explains that planetary objects such as WASP-189B are very strange: “They have a permanent day side, which always comes in the starlight, and accordingly, a permanent side of night.” This means that its atmosphere is completely different from that of our solar system’s gas giants Jupiter and Saturn. “Based on observations using Chio.PPS, we estimate the temperature of WASP-189B to be 3,200 degrees Celsius. Planets like WASP-189B are called” ultra-hot Jupiters. ” At such temperatures iron melts, and it also becomes gaseous. This object is one of the most extreme planets we have ever known, “says Lendl.

Very accurate brightness measurement

“We can’t see the planet itself because it’s so far away and its host is so close to the star, so we have to rely on indirect methods,” Lendl explains. For this, Ch EO Ips uses a very bright brightness measurement: when a planet passes in front of a star visible from Earth, the star appears blurred for a while. This phenomenon is called transport. Says Monica Lendl: “Because Exoplanet WASP-189B is so close to its star, part of its day is so bright that we can even measure the ‘missing’ light when the planet passes behind its star; this is called intelligence. We have observed many such spies of WASP-189b with chaps.It seems that the planet does not reflect many star galaxies.Instead, most of the starlight is absorbed by the planet, warming it and making it glow. ”

Researchers believe that the planet is not very reflective because no clouds are present on its side of the day. “This is not surprising, since theoretical models Dello tells us that clouds do not form at such high temperatures.”

“We also found that the transport of gas giants against its star is asymmetric. This happens when the star has bright and dark zones on its surface. Thanks to CHIPPS data, we can conclude that the star itself So fast that its shape is no longer round, but elliptical. The star is pulling outward at its equator. “

The star around which WASP-189B orbits is very different from the Sun. Monica Lendl says, “The star is significantly larger than our Sun and is 2000 degrees Celsius warmer. Because it is so hot, the star is not as blue and yellow-white as the Sun.”

“Only a few planets are known to orbit such stars, and this system is by far the brightest,” says Willie Benz. As a result, it forms a benchmark for further study. “We expect more spectacular findings on the exoplanet for observations with Cheoeps. Further papers are already in preparation.”