Extreme exoplanet – Jupiter is so hot it rains iron

It is considered very hot Jupiter A place where iron evaporates, condenses on the night side and then falls from the sky like rain – fiery, hell-like WASP-76b extrasolar planet It may be more exciting than scientists realized.

An international team, led by scientists at Cornell University, University of Toronto and Queen’s University Belfast, reports the discovery of ionized calcium on the planet — indicating more atmospheric temperature than previously thought, or strong winds in the upper atmosphere.

The detection was detected in high-resolution spectra obtained with Gemini North near the summit of Mauna Kea in Hawaii.

Hot Jupiters are named because of their high temperature, due to their proximity to their stars. WASP-76b was discovered in 2016, about 640 light-years from Earth, but so close to its F-type star, slightly hotter than the Sun, that the giant planet completes one orbit every 1.8 Earth days.

The research findings are the first from a multi-year project led by Cornell, Exoplanets with the Gemini Spectroscopic Survey, or ExoGemS, that explores the diversity of planets’ atmospheres.

“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 space worlds — from those hot enough to harbor iron rain to others with milder climates,” said co-authors Ray Jayawardana and Harold Tanner. Dean of the College of Arts and Sciences at Cornell University and Professor of Astronomy:

“It is remarkable that with modern telescopes and instruments, we can already learn a lot about the atmosphere – its components, physical properties, presence of clouds and even large-scale wind patterns – of planets orbiting stars hundreds of light-years away,” Jayawardhana said.

A rare trio of spectral lines observed in highly sensitive observations of the atmosphere of exoplanet WASP-76b, published in Astrophysical Journal Letters on September 28 and presented on October 5 at the annual meeting of the Division of Planetary Sciences of the American Astronomical Society.

“We are seeing a lot of calcium; “It’s a really strong advantage,” said first author Emily Diebert, a doctoral student at the University of Toronto, and her advisor, Jayawardana.

“This spectroscopic signature of ionized calcium could indicate that an exoplanet has very strong winds in the upper atmosphere,” Diebert said. “Or that the temperature of the atmosphere on an exoplanet is much higher than we thought.”

Because WASP-76b is tidal closed – this side of it is always facing the star – it has a perpetual night side with a relatively cool temperature of 2,400 degrees. F average temperature. Its diurnal side, facing the star, has an average temperature of 4,400 degrees Fahrenheit.

Diebert and her colleagues examined the temperate temperature region, on the fringes of the planet between day and night. “The exoplanet is moving rapidly in its orbit, and in this way we were able to separate its signals from the starlight,” she said. “You can see that the calcium footprint on the spectra is moving fast with the planet.”

The ExoGemS survey — which aims to study 30 or more planets — was led by Jake Turner, Carl Sagan’s fellow at NASAThe Hubble Fellowship Program, located in the Cornell University (A&S) Department of Astronomy, is also recommended by Jayawardhana.

Astronomers continue to dig deeper into understanding exoplanets — which were only a dream two decades ago. “Our work and that of other researchers is paving the way for exploring the atmospheres of terrestrial worlds outside our solar system,” Turner said.

Reference: “Detection of Ionized Calcium in the Atmosphere of Superheated Jupiter WASP-76b” by Emily K. Debert, Ernst GWD Mooy, Ray Jayawardana, Jake D. Turner, Andrew Raiden Harper, Luca Fossati, Kali E. Hood, Jonathan J. Fortney, Laura Flagg, Ryan MacDonald, Roman Allart and David K. Singh, 28 Sep 2021 Available Here. Astrophysical Journal Letters.
DOI: 10.3847 / 2041-8213 / ac2513

Other authors on the paper include Ernst JWD Moog of Queen’s University Belfast. Luca Fossati of the Austrian Academy of Sciences; Callie E. Hood and Jonathan J. Fortney, both from University of California, Santa Cruz; Romain Alart of the University of Montreal; and David K. Singh of Johns Hopkins University. Cornell researchers included Andrew Redden-Harper and Laura Flagg, both in the Jayawardhana group, and Ryan MacDonald. Portions of this research were funded by NASA.

Gemini North is part of the International Gemini Observatory, a program of the National Science Foundation NOIRLab.