Take a look at the planet Kelt 20-b, a hot Jupiter located 450 ly away and orbiting a hot A type star. This world orbits every 3.5 days at a distance just 5% the Earth’s distance from the sun. This charbroiled planet was recently studied by Yale’s Extreme PREcision Spectrometer (EXPRES), and scientists were able to study the planet’s atmosphere as it went from beside its host star to directly in front. KELT-20’s light passed through its planet’s atmosphere, some of that light was absorbed out, and the exact colors of those dark bands of absorption tell us what chemicals are present. Thanks to the light gathering power and resolution of the 4.3 m Lowell Discovery that was used, they could actually see gaseous iron, magnesium, and chromium. They also noted differences between the dawn and dusk sides of the world.  These differences will allow collaboration scientists to create atmospheric circulation models. These are still early days for both this discovery and this instrument, which are described in a new publication in Astronomy & Astrophysics that was led by Jens Hoeijmakers.

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Yale’s EXPRES looks to the skies of a scorching, distant planet (Yale News)