Planet retains atmosphere despite extreme heat

A planet called TOI-561 b, located 280 light-years from Earth, has surprised scientists by keeping its atmosphere despite being extremely close to its star. This finding challenges previous assumptions about how planets lose their atmospheres in such harsh conditions.

Planet orbits its star in less than eleven hours

TOI-561 b has a radius 1.4 times that of Earth and completes one orbit around its star in less than eleven hours. This proximity means it is subjected to intense stellar radiation and wind, which should have stripped away its atmosphere long ago.

James Webb Space Telescope observed the planet

The James Webb Space Telescope observed TOI-561 b for thirty-seven consecutive hours using the NIRSpec instrument. This allowed scientists to record the planet’s radiation between 3 and 5 micrometers across its orbit, revealing details about its day and night sides.

Planet’s temperature is extremely high

The planet’s day side reaches approximately 2,050 kelvins, or about 1,780 °C. If it had no atmosphere, its temperature would be closer to 3,200 kelvins. This suggests the atmosphere is playing a role in moderating the extreme heat.

Planet reflects light like Venus

TOI-561 b reflects about three-quarters of the light it receives, similar to how Venus reflects sunlight. This high reflectivity may be due to vaporized rock clouds, which could act as a protective layer, helping the planet retain its atmosphere.

Scientists propose vaporized rock clouds as explanation

Astronomers suggest that vaporized rock clouds, composed of silicates, might be responsible for the observed light reflection and atmospheric retention. This idea is presented as a working hypothesis to explain how TOI-561 b has managed to keep its atmosphere despite its extreme environment.