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James Webb Reveals Metal-Rich Chemistry of HR 8799 Planets

3/13/2026

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Summary

Story summary

Researchers using the James Webb Space Telescope found that the four gas giants in HR 8799 share a metal-rich chemistry.
The chemistry indicates they formed through core accretion without significant collisions.
The planets weigh 5 to 10 Jupiter masses and began forming early, efficiently capturing dust rich in carbon, oxygen, and sulfur, implying a chaotic but model-compatible environment.

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Story summary

Researchers using the James Webb Space Telescope found that the four gas giants in HR 8799 share a metal-rich chemistry.
The chemistry indicates they formed through core accretion without significant collisions.
The planets weigh 5 to 10 Jupiter masses and began forming early, efficiently capturing dust rich in carbon, oxygen, and sulfur, implying a chaotic but model-compatible environment.