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JWST Uncovers Ancient Atmosphere of Hot Planet TOI-561 b

9/24/2025

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Summary

Story summary

The James Webb Space Telescope (JWST) reveals a thick atmosphere around TOI-561 b.
TOI-561 b is a small, hot, old planet orbiting close at 2,300 kelvins.
The atmosphere may have persisted for billions of years.
Its dayside appears cooler than expected, according to JWST measurements.
The finding could illuminate how atmospheres originated in our solar system.

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Story summary

The James Webb Space Telescope (JWST) reveals a thick atmosphere around TOI-561 b.
TOI-561 b is a small, hot, old planet orbiting close at 2,300 kelvins.
The atmosphere may have persisted for billions of years.
Its dayside appears cooler than expected, according to JWST measurements.
The finding could illuminate how atmospheres originated in our solar system.