May 7 (UPI) — It’s always sunny on WASP-96b.
After analyzing the distant gas giant’s atmosphere, astronomers determined there is never a cloud in the skies of WASP-96b.
Scientists at the University of Exeter used the 8.2-meter Very Large Telescope in Chile to photograph the exoplanet — located 980 light-years from Earth — as it passed in front of its host star, found in the constellation Phoenix. By analyzing the spectral patterns created as light from its sun passed through the exoplanet’s atmosphere, researchers were able to characterize its composition.
Because different molecules absorb and reemit light in unique ways, spectral measurements can reveal the presence of specific chemicals.
The new analysis of WASP-96b, detailed Monday in the journal Nature, yielded the full spectral signature of sodium. Sodium’s fingerprint can only be measured in cloudless atmospheres.
The faraway gas giant is 20 percent larger than Jupiter, boasts a mass similar to Saturn’s and hosts daily temperatures approaching 1,300 Kelvin. Astronomers refer to the gas giant as a “hot Saturn.”
“We’ve been looking at more than twenty exoplanet transit spectra,” Exeter research Nikolay Nikolov said in a news release. “WASP-96b is the only exoplanet that appears to be entirely cloud-free and shows such a clear sodium signature, making the planet a benchmark for characterization.”
Researchers believe the new findings will help planetary scientists more accurately identify and characterize the atmospheres of other exoplanets.
“It is difficult to predict which of these hot atmospheres will have thick clouds,” said Jonathan J. Fortney, an astronomer at the University of California, Santa Cruz. “By seeing the full range of possible atmospheres, from very cloudy to nearly cloud-free like WASP-96b, we’ll gain a better understanding of what these clouds are made of.”
The analysis of WASP-96b suggests its atmosphere hosts concentrations of sodium similar to those found within our own solar system. During future transits, scientists hope to measure the amounts of
water, carbon monoxide and carbon dioxide in the hot Saturn’s atmosphere.