Reuters, WASHINGTON
In Earth’s upper atmosphere, a fast-moving band of air called the jet stream blows with winds of more than 442kph, but they are not the strongest in our solar system.
The comparable high-altitude winds on Neptune reach about 2,000kph.
However, those are a mere breeze compared with the jet stream on a planet called WASP-127b.
An image released on Tuesday by the European Southern Observatory depicts WASP-127b, a planet about 520 light-years from Earth, and its supersonic jet winds that move around the planet’s equator at about 33,000kph.
Photo: AFP / L. Calcada / European Southern Observatory
Astronomers have detected winds howling at about 33,000kph on the large gaseous planet in our Milky Way galaxy approximately 520 light-years from Earth in a tight orbit around a star similar to our sun.
The supersonic jet-stream winds circling WASP-127b at its equator are the fastest of their kind on any known planet.
“There is an extremely fast circumplanetary jet wind found on the planet. The velocity of the winds is surprisingly high,” said astrophysicist Lisa Nortmann of the University of Gottingen in Germany, lead author of the study published on Tuesday in the journal Astronomy & Astrophysics.
More than 5,800 planets beyond our solar system — called exoplanets — have been discovered. WASP-127b is a type called a “hot Jupiter,” a gas giant that orbits very close to its host star. WASP-127b’s diameter is about 30 percent larger than Jupiter, our solar system’s largest planet, but its mass is only about 16 percent that of Jupiter, making it one of the least dense — puffiest — planets ever observed.
“WASP-127b is a gas giant planet, which means that it has no rocky or solid surface beneath its atmospheric layers. Instead, below the observed atmosphere lies gas that becomes denser and more pressurized the deeper one goes into the planet,” said astrophysicist and study coauthor David Cont of Ludwig Maximilian University of Munich in Germany.
It orbits its star every roughly four days at just about 5 percent of the distance between Earth and the sun, leaving it scorched by stellar radiation.
Like our moon is to Earth, one side of WASP-127b perpetually faces its star — the day side. The other side always faces away — the night side. Its atmosphere is about 1,127°C, with its polar regions less hot than the rest.
The fact that a hot Jupiter’s day side is highly irradiated is believed to be a major driver of atmospheric dynamics.
“Answering the question of what drives these intense winds is challenging, as several factors influence wind patterns in exoplanet atmospheres,” Cont said.
“The primary source of energy for these winds is the intense irradiation from the host star,” he added.
The researchers tracked the speed of molecules in the planet’s atmosphere using an instrument called CRIRES+ on the European Southern Observatory’s Chile-based Very Large Telescope. They made the observations using the “transit” method, observing changes in the host star’s brightness when the planet passes in front of it, from the perspective of a viewer on Earth.
