The winds blowing on the planet WASP-127b are the fastest ever observed. This is what a study published by a team of astronomers in the journal Astronomy & Astrophysics reveals.
WASP-127b is a gas planet, located 520 light years from Earth. It orbits a star similar to our Sun. Its diameter is 30% larger than that of Jupiter (the largest planet in our solar system), although its mass is only about 16% that of Jupiter. These characteristics make it one of the least dense and therefore most bloated planets ever detected. Particular characteristics which could explain the winds which attack it.
Supersonic winds
According to Reuters, the winds observed by scientists are jet streams (jet-stream in English). These are air currents that circulate around WASP-127b at its equator. According to experts, these winds blow at an impressive supersonic speed of 33,000 km/h.
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Similar currents also affect other planets, but never with such power. In the upper atmosphere of the Earth, a current of this type exists, but never exceeds 442 km/h. These results particularly intrigued scientists, such as astrophysicist Lisa Nortmann, lead author of the study, who was surprised to find that the wind speed was so “surprisingly high”.
-Towards a better understanding of the atmosphere of exoplanets
The researchers then tried to understand what could cause these currents. “Answering the question of what powers these intense winds is difficult, because several factors influence wind patterns in exoplanet atmospheres“, said David Cont, astrophysicist and co-author of the study. The main source of energy for these winds would be the intense radiation of the host star. WASP-127b gravitates very close to its star. This makes d she is a “hot Jupiter” type planet (hot Jupiter in English), with a temperature greater than 1,000 kelvins or 730 C°. The kelvin being the basic unit of measurement of thermodynamic temperature.
The researchers found that WASP-127b’s atmosphere reached about 1,400 kelvins, or 1,127 °C. They also found that one of its sides, the day side, permanently faces its star. The fact that this side is highly irradiated is considered a major factor in atmospheric dynamics and therefore in the formation of wind patterns.
However, other factors could explain this phenomenon. Thanks to observations from an instrument called CRIRES+, installed on the Very Large Telescope of the European Southern Observatory, based in Chile, researchers hope to make new discoveries to better understand the atmosphere of exoplanets.
