Thursday, May 19, 2022

An extreme exoplanet is more sizzling than scientists thought

The fiery and inferno-like exoplanet WASP-76b maybe even more sizzling than scientists thought.

In 2016, scientists discovered a gaseous exoplanet called WASP-76b known for vaporizing iron in its atmosphere. This extreme exoplanet, which lies about 640 light-years from Earth, is 1.8 times the size of Jupiter in our Solar System.

In a new study by the Queen’s University Belfast, Cornell University, and the University of Toronto, scientists reported discovering ionized calcium in the exoplanet.

In the high-resolution analysis obtained from the Gemini North telescope, scientists obtained a rare trio of spectral lines in the exoplanet’s atmosphere. These lines are caused by ionized calcium in the planet’s upper atmosphere.

Dr. Ernst de Mooij from the School of Mathematics and Physics at Queen’s University Belfast was involved in analyzing the data. He comments: “This detection of ionized calcium is the first result from the ExoGemS survey and shows the impact of the extreme conditions on the atmospheres of WASP-76b.”

First author and University of Toronto doctoral student Emily Deibert explains: “We see so much calcium, it’s a powerful feature. This spectral signature of ionized calcium could indicate that the exoplanet has very strong upper atmosphere winds. Or the atmospheric temperature on the exoplanet is much higher than we thought.”

This hot Jupiter exoplanet orbits its star every 1.8 Earth days and is 30 times closer to its star than the Earth is to the Sun. This study that offers insights into the planet’s upper atmosphere suggests that the upper atmosphere is either hotter than expected or that strong winds are present.

Co-author Dr. Ray Jayawardhana, the Harold Tanner Dean of the College of Arts and Sciences and a professor of astronomy at Cornell University, explains“As we do ‘remote sensing’ of dozens of exoplanets, spanning a range of masses and temperatures, we will develop a complete picture of the true diversity of alien worlds – from those hot enough to harbor iron rain to others with more moderate climates, from those heftier than Jupiter to others not much bigger than the Earth.”

“It’s remarkable that with today’s telescopes and instruments, we can already learn so much about the atmospheres – their constituents, physical properties, presence of clouds, and even large-scale wind patterns – of planets that are orbiting stars hundreds of light-years away.”

Dr. De Mooij says: “These observations are not only revealing more details of exoplanet atmospheres now but are also paving the way for investigating ever-smaller planets with the next generation of telescopes, such as the Extremely Large Telescope.”

Journal Reference:
  1. Emily K. Deibert et al. Detection of Ionized Calcium in the atmosphere of the Ultra-hot Jupiter WASP-76b. DOI: 10.3847/2041-8213/ac2513


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