Astrophysicists found an exoplanet the size of Jupiter has a tail of gas seven times its own length—around 350,000 miles—resulting from its gas atmosphere burning off and being shaped by stellar winds, a type of discovery the scientists say is “pivotal” for understanding how planets evolve over time.
This handout image of the giant, active galaxy NGC 1275, obtained August 21, 2008 was taken using ... [+]
The team of astrophysicists, led by some at the University of California, Los Angeles, discovered the atmosphere leaving WASP-69b—a gaseous planet the size of Jupiter that orbits its host star extremely closely—is forming a “comet-like tail” as it’s burned off and “shaped by stellar winds,” according to a new study published Tuesday.
The new information that the host star is not just causing the planet to lose gas but is also “physically shepherding” that lost gas to form the long tail gives insight into the role of stellar winds, according to a release from UCLA.
Before this discovery, scientists knew the planet was losing atmosphere at a high rate because of how closely it orbits its host star, but the exoplanet was believed to have no tail, or just a “hint of a tail.”
Erik Petigura, co-author and professor of physics and astronomy at UCLA, called the planet a “gem,” and said the new discovery provides the “rare opportunity to study atmospheric mass loss in real time and understand the critical physics that shape thousands of other planets,” according to the UCLA release.
200,000 tons per second. That’s the rate at which WASP-69b is losing its atmosphere because of how closely it is orbiting its star.
WASP-69b is so big—with around 90 times Earth’s mass—that even though it’s losing an “enormous amount” of mass, lead author Dakotah Tyler said it isn’t at risk of “losing its entire atmosphere within the star’s lifetime.”