This signature is unique from what astronomers see in the atmospheres of hot-Jupiters orbiting cooler stars, like our Sun. They radiate through the hot, transparent upper atmosphere that is produced by the inversion layer. On KELT-20b the UV radiation from the star is heating metals in the atmosphere, which makes for a very strong thermal inversion layer.Įvidence came from Hubble's detection of water in near-infrared observations, and from NASA's Spitzer Space Telescope's detection of carbon monoxide. There have been lots of theories, but now we have the first observational data," Fu said.īy comparison, on Earth, ozone in the atmosphere absorbs UV light and raises temperatures in a layer between 7 to 31 miles above Earth's surface. "Until now we never knew how the host star affected a planet's atmosphere directly. On this planet a blast of ultraviolet light from its parent star is creating a thermal layer in the atmosphere, much like Earth's stratosphere.
In a paper published in the January 24 issue of Astrophysical Journal Letters, Guangwei Fu of the University of Maryland, College Park, reported on a super-hot Jupiter, KELT-20b, located about 400 light-years away. "We knew we had seen something really interesting with this silicon monoxide feature," said Josh Lothringer of the Utah Valley University in Orem, Utah. On the dark side, the silicon monoxide may cool enough to condense into rock that rains out of clouds, but even at dawn and dusk, the planet is hot enough to vaporize rock. Because one side of the planet permanently faces its star, the torrid atmosphere whips around to the nighttime side at super-hurricane speeds exceeding 2,000 miles per hour. On the daytime side the atmosphere is cloudless, and is enriched in silicon monoxide gas. In a paper in the April 7 journal Nature, astronomers describe Hubble observations of WASP-178b, located about 1,300 light-years away. Even though you know the basic chemistry and physics, you don't know how it's going to manifest in complex ways." But when you go to a distant exoplanet, you have limited predictive powers because you haven't built a general theory about how everything in an atmosphere goes together and responds to extreme conditions. "When you look at Earth, all our weather predictions are still finely tuned to what we can measure. "We still don't have a good understanding of weather in different planetary environments," said David Sing of the Johns Hopkins University in Baltimore, Maryland, co-author on two studies being reported. Studying extreme weather gives astronomers better insights into the diversity, complexity, and exotic chemistry taking place in far-flung worlds across our galaxy. This research goes beyond simply finding weird and quirky planet atmospheres. By subscribing, you agree to receive email related to Lab Manager content and products.
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