Astronomers utilizing NASA’s Transiting Exoplanet Survey Satellite (TESS) have recognized a dense, ultra-short-period sub-Earth planet transiting the brilliant, close by purple dwarf Gliese 367.
An artist’s impression of the sub-Earth exoplanet Gliese 367b. Image credit score: SPP 1992 (Patricia Klein).
Gliese 367 is situated some 31 light-years away from Earth within the constellation of Vela.
Also referred to as GJ 367, CD-45 5378, HIC 47780, TIC 34068865 and TOI-731, this star is assessed as an M-dwarf — a sort of star that usually hosts a number of planets.
“For this class of star, the habitable zone would be somewhere between a two- to three-week orbit,” stated Dr. George Ricker, an astronomer with the Kavli Institute for Astrophysics and Space Research at MIT.
“Since this star is so close by, and so bright, we have a good chance of seeing other planets in this system. It’s like there’s a sign saying, ‘Look here for extra planets!’”
The newfound planet, named Gliese 367b, has an orbital interval of solely 7.7 hours.
With a diameter of simply over 9,000 km (5,592 miles), the alien world is barely bigger than Mars.
Gliese 367b is a rocky planet and certain incorporates a strong core of iron and nickel, just like Mercury’s inside.
“We’re finding a Mars-sized planet that has the composition of Mercury,” stated Dr. Roland Vanderspek, an astronomer within the Department of Physics and the Kavli Institute for Astrophysics and Space Research at MIT.
“It’s among the smallest planets detected to date, and it’s spinning around an M-dwarf on a very tight orbit.”
“The high density indicates the planet is dominated by an iron core,” stated Dr. Szilárd Csizmadia, an astronomer with the Institute of Planetary Research at DLR (German Aerospace Center).
“These properties are similar to those of Mercury, with its disproportionately large iron and nickel core that differentiates it from other terrestrial bodies in the Solar System.”
Due to its excessive proximity to its star, Gliese 367b is blasted with 500 occasions extra radiation than what the Earth receives from our Sun. As a outcome, its dayside boils at as much as 1,500 levels Celsius (2,732 levels Fahrenheit).
Under such excessive temperatures, any substantial environment would have lengthy vaporized away, together with any indicators of life, at the least as we all know it.
“We already know a few of ultra-short-period planets, but their origins are currently unknown,” stated Dr. Kristine Lam, an astronomer with the Institute of Planetary Research at DLR (German Aerospace Center).
“By measuring the precise fundamental properties of the ultra-short-period planet, we can get a glimpse of the system’s formation and evolution history.”
“Understanding how these planets get so close to their host stars is a bit of a detective story,” stated Dr. Natalia Guerrero, a member of the TESS science group.
“Why is this planet missing its outer atmosphere? How did it move close in? Was this process peaceful or violent? Hopefully this system will give us a little more insight.”
The discovery is reported in a paper within the journal Science.
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Kristine W.F. Lam et al. 2021. GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a close-by purple dwarf star. Science 374 (6572): 1271-1275; doi: 10.1126/science.aay3253