The exoplanet WASP-76b is a kind of ultra-hot Jupiter. So much so, that there the iron vaporizes, condenses overnight and then falls back as rain. Now, an international team of scientists reveals that this hellish place could be even warmer than previously thought.
The article, published in the Astrophysical Journal Letters , reveals the discovery of ionized calcium on the planet, something that suggests either a higher atmospheric temperature than previously thought, or the existence of strong winds in its upper atmosphere.
The name ‘hot Jupiters’ is applied to exoplanets with high temperatures, mainly due to the proximity to their stars. WASP-76b, discovered in 2016, is about 640 light years from Earth, and so close to its F-type star – slightly warmer than the sun – that the giant planet completes one orbit every 1.8 Earth days.
More and more exoplanets are being described
“As we remotely sense dozens of exoplanets, spanning a range of masses and temperatures, we will develop a more complete picture of the true diversity of alien worlds, from those hot enough to host iron rain to others with climates. more moderate, from those heavier than Jupiter to others not much larger than Earth, ”explains co-author Ray Jayawardhana, dean of the College of Arts and Sciences at Cornell University and professor of astronomy.
“It is amazing that with today’s telescopes and instruments we can already learn so much about the atmospheres – their components, physical properties, the presence of clouds and even large-scale wind patterns – of planets orbiting stars hundreds of light-years away.” indicates the researcher.
The group detected a strange trio of spectral lines in highly sensitive observations of the atmosphere of exoplanet WASP-76b. “This spectral signature of ionized calcium could indicate that the exoplanet has very strong winds in the upper atmosphere,” explains Emily Deibert, a doctoral student at the University of Toronto and lead author of the research. “The other possibility is that the atmospheric temperature on the exoplanet is much higher than we think.”
Referencia: Deibert et al. 2021. Detection of Ionized Calcium in the Atmosphere of the Ultra-hot Jupiter WASP-76b. Astrophysical Journal Letters 919 L15
