April 14, 2021
The chemical fingerprint of exoplanet HD 209458b’s atmosphere reveals as many as 6 molecules and that it has migrated inwards from its birthplace much farther out in its star system.
Artist’s concept of exoplanet Osiris – aka HD 209458b – as it transits in front of its star. Note the illuminated crescent of the planet, where the colors illustrate the light spectra that – like a chemical fingerprint – let astronomers identify as many as 6 molecules in the planet’s atmosphere. “It’s the first time so many molecules have been measured and points to an atmosphere with more carbon than oxygen”, they said. Image via University of Warwick/ Mark Garlick.
February 26, 2021
For the first time, astronomers have detected the vaporized remains of the crusts of long-dead Earth-like and Mars-like planets in the atmospheres of white dwarf stars.
Artist’s concept of planetary crust fragments being vaporized around a white dwarf star. Image via University of Warwick/ Mark Garlick.
Finding other Earth-
like planets in our Milky Way galaxy has been a holy grail of exoplanet research. Astronomers have found Earth-
sized exoplanets. But is an Earth-sized planet going to be Earth-like? We still don’t know. Now, though, scientists at the University of Warwick in the U.K. have announced another clue that some exoplanets can, and do, have Earth-like compositions. The results come not from the planets themselves, but rather the vaporized remains of their crusts in the atmospheres of white dwarf stars.
E-Mail
IMAGE: Remnants of planetary crust disintegrating under the tidal forces around a cool white dwarf. Material in the disc becomes vapourised close to the central star and flows onto the white. view more
Credit: University of Warwick/Mark Garlick
Observations of lithium and potassium around white dwarf stars point to remains of rocky planet crusts
Analysis by astronomers led by University of Warwick shows chemical composition of crusts is very similar to Earth s continental crust
The outer layers of the white dwarfs contain up to 300,000 gigatonnes of rocky debris, which includes up to 60 gigatonnes of lithium and 3,000 gigatonnes of potassium
WASP-107b was discovered in 2017, and quickly found to be weird. It’s a hot Jupiter, a gas giant orbiting its star very closely, at a distance of only 9 million kilometers. Mercury orbits the Sun at roughly 60 million kilometers, so WASP-107b is
close. The host star, WASP-107, is an orange dwarf, smaller and cooler than the Sun, but still not something you want to be that close to unless baking your entire planet is your goal. The temperature of WASP-107b is likely around 1,000° C (1,800°F).
Zoom In
Artwork of a hot Jupiter , an exoplanet the size of Jupiter but orbiting its host star at a small fraction of Earth s distance to the Sun. Credit: University of Warwick/Mark Garlick