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Over the past decade, exoplanet missions as NASA’s Kepler mission and TESS (Transiting Exoplanet Survey Satellite) have found over 4,000 alien worlds across the vast universe. But a newcomer to the hunt is giving these two space telescopes a run for their money.
The European Space Agency CHcharacterizing meXINdamn Sa satellite (or CHEOPS) just made its first exoplanet discovery, and it’s amazing.
The discovery was detailed in a study published Monday in the journal. Astronomy and Astrophysics.
CHEOPS launched in December 2019 to observe nearby stars and the strange worlds that can orbit them.
One of these stars is 2,000 times hotter than our Sun, so it appears to glow a brilliant blue.
“Only a few planets are known to exist around such hot stars,” Monika Lendl, a researcher at the University of Geneva, Switzerland, and lead author of the new study, said in a statement.
The exoplanet, nicknamed WASP-189 b, was captured speeding its way around this ultra-hot star. WASP-189 b is a hot planet Jupiter, a gas giant similar to the Jupiter in our own Solar System, but with more extreme temperatures.
The scorching exoplanet is about 20 times closer to its star than Earth is to the Sun, completing a full orbit in just 2.7 days. Temperatures in WASP-189 b reach sweltering 3,200 degrees Celsius, the scientists report.
WASP-189 b is quite large, measuring almost 1.6 times the radius of the largest planet in the Solar System, Jupiter.
When crossing in front of its star, WASP-189 b causes a noticeable drop in light from the star.
“WASP-189b is also the brightest hot Jupiter that we can observe when it passes in front of or behind its star, which makes the whole system really intriguing,” Lendl said.
CHEOPS ‘first find is one of the hottest and most extreme exoplanets ever found.
The planet’s host star is also quite intriguing. The star is not perfectly round, but is larger and cooler at the equator than at the poles, making the star’s poles appear brighter, according to the researchers.
“It’s spinning so fast it’s being pushed out at its equator,” Lendl said. “Added to this asymmetry is the fact that the orbit of WASP-189 b is tilted; It does not travel around the equator, but passes close to the star’s poles. “
For a planet to develop this tilted orbit, it may have formed farther away from its star and been drawn toward its host over time. This could have happened if another object, such as a second star, pushed the exoplanet closer to the star at some point during its past.
Studying an exoplanet like WASP-189 b helps scientists better understand the history of Jupiter’s hot planets and how these gas giants evolve.
“By tracking exoplanets in their orbits with CHEOPS, we can do a first-pass characterization of their atmospheres and determine the presence and properties of the clouds present,” said Kate Isaak, a CHEOPS project scientist at ESA, in a statement. It not only deepens our understanding of exoplanets, but also that of our own planet, the Solar System, and the broader cosmic environment. “
Abstract: The CHEOPS space mission dedicated to exoplanet tracking was launched in December 2019, equipped with the ability to perform photometric measurements at the 20 ppm level. As CHEOPS conducts its observations in a wide optical passband, it can provide information on reflected light from exoplanets and restrict short-wavelength thermal emission for hotter planets by observing occultations and phase curves. . Here, we report the first CHEOPS observation of an occultation, namely that of the hot Jupiter WASP-189 b, an MP ≈ 2MJ planet orbiting a type A star. We detect the occultation of WASP-189 b with high significance in individual measurements and we obtained a depth of concealment of dF = 87.9 ± 4.3 ppm based on four occultations. We compare these measurements with the model predictions and find that they are consistent with a non-reflective atmosphere heated to a temperature of 3435 ± 27 K, when inefficient heat redistribution is assumed. In addition, we present two transits of WASP-189 b observed by CHEOPS. These transits have an asymmetric shape that we attribute to the gravity darkening of the host star caused by its high rotation speed. We used these measurements to refine the planetary parameters, finding a transit ∼ 25% deeper compared to the discovery paper and updating the radius of WASP-189 to 1.619 ± 0.021RJ. Furthermore, we measured the projected orbital obliquity to be λ = 86.4 +2.9 −4.4 degrees, a value that is in agreement with a previous measurement of spectroscopic observations, and obtained a true obliquity of Ψ = 85.4 ± 4.3 degrees. Finally, we provide reference values for the photometric precision achieved by the CHEOPS satellite: for the star of magnitude V = 6.6, and using a binning of one hour, we obtain a residual RMS between 10 and 17 ppm in the individual light curves, and 5.7 ppm when combining all four visits.
