Is the sun getting hotter?

I went into this expecting the Sun to have been more or less constant for the whole history of life, wobbling a bit with sunspot cycles. That is wrong, and it is wrong by a lot. It is also a question that answers itself slightly sideways. The Sun is getting brighter, dramatically so. It is barely getting hotter. Those are different things, and the gap between them is the interesting part. ...

July 10, 2026 · 8 min · Nathan Broadbent