‘Bare’ super-earths offer clues to evolution of hot atmospheres


Share post:

A group of astronomers from the Astrobiology Center, the National Astronomical Observatory of Japan, the University of Tokyo, and other institutes, discovered two rocky super-Earth exoplanets lacking thick primordial atmospheres in very close orbits around two different red dwarf stars. These planets provide a chance to investigate the evolution of the atmospheres of hot rocky planets.

'Bare' super-earths offer clues to evolution of hot atmospheres
Artist’s conceptual image showing the sizes of the planets observed in this study. The radius of
TOI-1634 is 1.5 times larger than Earth’s radius and TOI-1685 is 1.8 times larger. The
planets would appear red, due to the light from the red dwarf stars they orbit
[Credit: Astrobiology Center]

In this research, the Subaru Telescope and other telescopes conducted follow-up observations of two planet candidates (TOI-1634b and TOI-1685b, originally identified by NASA’s TESS spacecraft) around red dwarf stars. Both candidates are in the constellation Perseus, and about the same distance from Earth; TOI-1634b is 114 light-years away and TOI-1685b is 122 light-years away. The team confirmed that the candidates are rocky super-Earths in ultra-short-period orbits taking less than 24 hours to complete a trip around their host stars.

The observations by the InfraRed Doppler (IRD) spectrograph mounted on the Subaru Telescope also measured the masses of these planets and provided insight into the internal and atmospheric structures of these planets. The results showed that the planets are “bare,” meaning that they lack primordial thick hydrogen-helium atmospheres, possibly due to interactions with the extremely close host stars. 

This makes room for a secondary atmosphere composed of gases released from within the planet. The results also show that TOI-1634b is one of the largest (1.8 Earth radii) and most massive (10 Earth masses) planets among the known ultra-short period rocky planets. These new planets offer excellent opportunities to study what kind of atmospheres, if any, can develop on ultra-short-period rocky planets, and provide clues to help understand how such unusual planets are formed.

Further observations by future telescopes including the James Webb Space Telescope aim to detect and characterize the atmospheres of these planets. Dr. Teruyuki Hirano, the lead author of this research, says “Our project to intensively follow-up planetary candidates identified by TESS with the Subaru Telescope is still in progress, and many unusual planets will be confirmed in the next few years.”

These results have been published in The Astronomical Journal.

Source: Subaru Telescope [September 26, 2021]

Support The Archaeology News Network with a small donation!



Related articles

Falling stars hold clue for understanding dying stars

An international team of researchers has proposed a new method to investigate the inner workings of supernovae explosions....

Early Earth was bombarded by series of city-sized asteroids

Scientists know that the Earth was bombarded by huge impactors in distant time, but a new analysis suggest...

Holes in the universe sharpen cosmic measurements

Regions of the Universe containing very few or no galaxies - known as voids - can help measure...

NASA satellite spots a mystery that’s gone in a flash

Pops of bright blue and green in this image of the Fireworks galaxy (NGC 6946) show the locations...

Total annihilation for supermassive stars

A renegade star exploding in a distant galaxy has forced astronomers to set aside decades of research and...

Bright areas on Ceres suggest geologic activity

If you could fly aboard NASA's Dawn spacecraft, the surface of dwarf planet Ceres would generally look quite...

New observations show planet-forming disc torn apart by its three central stars

A team of astronomers have identified the first direct evidence that groups of stars can tear apart their...

A galactic test will clarify the existence of dark matter

Researchers at the University of Bonn and the University of California at Irvine used sophisticated computer simulations to...