JWST Reveals Powerful Winds and Dense Atmosphere on Scorching Exoplanet TOI-561b

The astronomers found out that TOI-561b, a rocky exoplanet that is ultra-hot, has an unusually dense atmosphere despite the high rate of stellar radiation. The planet was found by the NASA TESS project and is approximately twice as heavy as Earth with an orbit that takes it a little over 10 hours. The NASA James Webb Space Telescope observations have revealed a temperature that is significantly lower than anticipated across both day and night sides, suggesting that there is effective redistribution of heat by high-velocity winds in a dense atmosphere.

Thick atmosphere detected by Webb

According to the new study, the data Webb offers by far is the best evidence that the rocky super-Earth still has an atmosphere. TOI-561b was observed by the telescope to have a daytime temperature of approximately 1,800 °C on its dayside, which is approximately 900 °C lower than that of a bare rock in perpetual starlight. The night was also a lot warmer than it was forecast. This indicates strong winds which move the heat around the Earth, meaning that there is a thick gaseous envelope. The models indicate that TOI-561b is surrounded by an atmosphere rich in volatiles, and this might be the reason for its low density.

A magma ocean may replenish the atmosphere

Previously, astronomers believed planets so close to a star would lose any atmosphere. The new data suggest TOI-561b's global magma ocean may continually outgas volatile gases, replenishing what the star strips away. Co-author Tim Lichtenberg likens the planet to a “wet lava ball” where escaping gases partially recondense into the molten interior. While TOI-561b is far too scorched for life, the discovery provides fresh insight into how rocky planets can form and maintain atmospheres.