All has to do with the center of mass of the sun vs. the center of mass of the solar system, which is primarily driven by the orbit of Jupiter. When the two align, the sun gets quiet.
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Very interesting comment. Any idea what the mechanism is? When you have alignment, what changes enough to affect the sun?
Yup. If the centers of mass of the sun and the solar system (primarily driven by the position of Jupiter) align, there is less turbulence and therefor less fusion within the sun. It gets quieter. When they don’t align, there is a lot more turbulence and therefore more fusion. This is not too dissimilar from how tides work on Earth. /this is a very simplified explanation