Gliese 367 b is a dark and hot sub-Earth with no atmosphere, study finds

Utilizing the James Webb Area Telescope (JWST), astronomers have investigated a close-by sub-Earth exoplanet often known as Gliese 367 b. The obtained outcomes point out that this alien world is darkish, scorching and lacks a detectable ambiance. The brand new findings have been published January 2 on the pre-print server arXiv.

Gliese 367 b (or GJ 367 b for brief, dubbed Tahay) was found in December 2021 with NASA’s Transiting Exoplanet Survey Satellite tv for pc (TESS). It orbits Gliese 367 (often known as Añañuca)—an M-dwarf of spectral sort M1.0V situated some 31 light years away, practically half the scale and mass of the sun. The system additionally harbors no less than two extra planets, situated farther from the host.

Earlier observations of Gliese 367 b have discovered that it’s about 30% smaller than the Earth and its mass is roughly 0.67 Earth lots. It has an equilibrium temperature of 1,367 Okay and encircles its parent star each 7.7 hours.

Now, a workforce of astronomers led by Michael Zhang of the College of Chicago has used JWST’s Mid-Infrared Instrument (MIRI) to characterize the ambiance of Gliese 367 b. The observations delivered extra insights into the properties and nature of this exoplanet.

“Utilizing the Mid-Infrared Instrument on JWST, we monitored GJ 367 b for 12.7 h, akin to 1.6 planetary orbits,” the researchers wrote within the paper.

The observations discovered that Gliese 367 b is a planet with no detectable ambiance, no warmth redistribution, and a darkish floor within the MIRI bandpass with a blackbody emission spectrum. The dayside temperature of Gliese 367 b was discovered to be 1,728 Okay, whereas its nightside temperature was estimated to be beneath 847 Okay.

In response to the paper, the outcomes rule out the chance that Gliese 367 b has a carbon dioxide ambiance with a stress of greater than 1 bar. It additionally excludes an outgassed ambiance with a stress of greater than 10 millibar (below closely decreasing circumstances), or an outgassed ambiance with a stress larger than 0.01 millibar (below closely oxidizing circumstances).

The collected knowledge recommend that Gliese 367 b ought to have a largely molten dayside. Subsequently, any volatiles within the silicate mantle of this planet must be partitioned into the ambiance. That’s the reason the authors of the paper concluded that Gliese 367 b will need to have no ambiance, except its bulk is freed from any volatiles.

Moreover, primarily based on the outcomes, the researchers suppose that the noticed lack of ambiance in Gliese 367 b signifies that the planet has significantly much less volatiles as an entire in comparison with Earth. They assume that this lack of atmosphere will be because of the removing of preliminary volatiles by intense stellar irradiation.

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