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Sun’s hidden boundary revealed for the first time by scientists

Scientists have mapped the Sun’s invisible outer boundary for the first time, revealing a chaotic edge where solar wind escapes magnetic control, reshaping how to understand space weather and stellar behaviour.

December 21, 2025 / 11:27 IST
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Alfvén surface of the Sun. (Image: CfA/Melissa Weiss)
Alfvén surface of the Sun. (Image: CfA/Melissa Weiss)

Scientists have mapped the Sun’s outer boundary for the first time. This breakthrough reveals where solar wind escapes magnetic control. It marks a historic moment in modern solar science. The finding reshapes understanding of how stars interact with space.

An unseen frontier shaping the Sun

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The boundary is known as the Alfvén surface. It surrounds the Sun far beyond its visible surface. Here magnetic forces weaken and particles break free. Beyond this line solar wind moves without resistance.

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