Astronomers have detected ferocious jet-stream winds reaching speeds of 20,500 miles per hour (33,000 km/h) on the exoplanet WASP-127b, the fastest atmospheric winds ever recorded on a known planet.
Located about 520 light-years away in the Milky Way galaxy, WASP-127b is a “hot Jupiter” — a large, gaseous planet with a close orbit around a star similar to our sun. The findings were published in the journal Astronomy & Astrophysics.
Supersonic Winds and Planetary Features
The powerful jet winds circle the planet’s equator, driven by intense stellar radiation. “The velocity of the winds is surprisingly high,” said astrophysicist Lisa Nortmann of the University of Göttingen in Germany, lead author of the study.
WASP-127b has a diameter 30% larger than Jupiter but only 16% of Jupiter’s mass, making it one of the puffiest planets ever discovered. With an orbital period of just four days, the planet is exposed to extreme radiation, resulting in an atmospheric temperature of about 2,060 degrees Fahrenheit (1,127 degrees Celsius).
Atmospheric Composition and Observations
The planet’s atmosphere, composed mainly of hydrogen and helium, also contains traces of carbon monoxide and water, which researchers identified using the CRIRES+ instrument on the European Southern Observatory’s Very Large Telescope in Chile.
Using the “transit” method—tracking changes in a star’s brightness when the planet passes in front of it—the team measured the speed of molecules in WASP-127b’s atmosphere.
“Answering the question of what drives these intense winds is challenging,” said astrophysicist David Cont of Ludwig Maximilian University of Munich. While intense irradiation from the host star is the primary energy source, other factors, such as planetary rotation and atmospheric dynamics, influence the wind patterns.
Expanding Exoplanetary Understanding
While higher wind speeds have been recorded on two other exoplanets, these were limited to winds traveling from their day side to night side, unlike the planet-circling jet streams observed on WASP-127b.
The discovery highlights the rapidly evolving field of exoplanet research. “We are moving beyond inferring average properties, such as global average temperature or chemical abundances, to exploring three-dimensional aspects of these atmospheres—such as studying winds, temperature variations, and chemical processes,” Cont said.
This breakthrough underscores how advancements in technology and analysis techniques continue to unveil surprises about the atmospheres of distant worlds.