Supersonic winds discovered on distant exoplanet WASP-127b

Astronomers have uncovered a remarkable phenomenon on the exoplanet WASP-127b, where jet-stream winds reach astonishing speeds of 20,500 miles per hour (33,000 km/h). These supersonic winds, the fastest ever detected on any known planet, circle the gaseous giant’s equator at velocities far surpassing any atmospheric winds found in our solar system.  

WASP-127b, located approximately 520 light-years from Earth in the Milky Way galaxy, is classified as a “hot Jupiter”—a gas giant closely orbiting its host star. The planet’s diameter is about 30% larger than Jupiter, making it one of the largest exoplanets observed. However, it is also among the least dense, with only 16% of Jupiter’s mass, earning it the description of a “puffy” planet.  

The findings, published in the journal Astronomy & Astrophysics, provide new insights into the atmospheric dynamics of exoplanets. "There is an extremely fast circumplanetary jet wind found on the planet. The velocity of the winds is surprisingly high," said Lisa Nortmann, an astrophysicist at the University of Göttingen in Germany and the study’s lead author.  

A blazing, dynamic atmosphere  

This extraordinary planet orbits its host star every four days at a mere 5% of the distance between Earth and the Sun. As a result, WASP-127b is subjected to intense stellar radiation. Like Earth’s Moon, it is tidally locked, meaning one side of the planet always faces the star (the scorching day side), while the other remains in perpetual darkness (the cooler night side).  

The planet’s atmosphere reaches searing temperatures of around 2,060°F (1,127°C), with its polar regions slightly less hot than the equatorial zones. Composed primarily of hydrogen and helium, the atmosphere also contains traces of complex molecules, including carbon monoxide and water—elements identified during this research.  

"The primary source of energy for these winds is the intense irradiation from the host star," explained study co-author David Cont of Ludwig Maximilian University of Munich. However, other factors, such as temperature gradients and planetary rotation, also shape the observed wind patterns.  

Unprecedented detection  

The supersonic winds on WASP-127b differ from the atmospheric winds previously detected on other exoplanets, which typically flow from the day side to the night side. In this case, the winds circulate entirely around the planet's equator—a unique discovery in exoplanetary studies.  

Researchers tracked the movement of molecules in the planet’s atmosphere using the CRIRES+ instrument on the European Southern Observatory’s Very Large Telescope in Chile. The team employed the “transit” method, observing fluctuations in the star’s brightness as WASP-127b passed in front of it from Earth’s perspective.  

This approach, combined with advancements in instrumentation and analytical techniques, is allowing astronomers to delve deeper into the three-dimensional dynamics of exoplanetary atmospheres.  

A rapidly evolving field  

"We are moving beyond inferring average properties, such as global average temperature or chemical abundances, to exploring the three-dimensional aspects of these atmospheres—winds, temperature variations, and chemical processes across different longitudes and latitudes," Cont noted.  

Such discoveries highlight the complexity of exoplanetary systems and the vast possibilities for further exploration. As technology continues to improve, researchers anticipate uncovering even more surprises in the atmospheres of distant worlds.  

WASP-127b’s supersonic winds serve as a stunning reminder of the dynamic and diverse conditions that exist beyond our solar system, offering a glimpse into the untapped mysteries of the universe.