WASP-127b is a gas giant 500 light-years from Earth unlike anything astronomers have ever seen. This planet is larger than Jupiter but has much less mass, making it extremely “spongy”. Currently, scientists detect supersonic winds sweeping across the equator of WASP-127b. These winds can reach speeds of 33,000 km/h, six times faster than the rotation speed of the planet itself.
“We have never seen anything like this before,” said Lisa Nortmann, a scientist at the University of Göttingen, Germany, who led the research team. “Part of the planet’s atmosphere moves towards us at high speed while the rest moves away from us at the same speed. This signal shows that there is a very fast supersonic wind around the equator of the planet”.
Wind speeds on WASP-127b are extremely fast, reaching nearly 9 km/s (33,000 km/h), making it the fastest wind ever recorded for a jet stream around the planet. Compared to it, the fastest winds ever observed in the solar system are located at Neptune with a modest speed of 2,000 km/h.
The team used the CRIRES+ instrument on the European Southern Observatory’s (ESO) Very Large Telescope (VLT) to map the weather and composition of WASP-127b. A planet’s composition is determined through analysis of how starlight passes through it. Analysis results revealed the existence of water vapor and carbon monoxide in the planet’s upper atmosphere.
The team observed a “double peak” in the speed of atmospheric material on the planet. This indicates that many places in the atmosphere are moving very quickly, both toward and away from the point of observation on Earth. They concluded that the rapid movement was caused by powerful winds rotating around the planet’s equator. WASP-127b’s weather map reveals some interesting temperature fluctuations. Notably, the poles are cooler than many other regions of the planet. Additionally, the team observed a small temperature difference between the day side and the night side, suggesting that WASP-127b has complex weather patterns like Earth and other planets in the solar system, according to Fei. Yan, a professor at the University of Science and Technology of China, co-authored the study.
ESO’s Extremely Large Telescope (ELT), under construction in Chile, will enhance its ability to study weather patterns on distant planets. The team describes WASP-127b’s supersonic wind findings in detail in the journal Astronomy & Astrophysics.