Fanfan 🐻 nihiliste ✋️🔺️🤚 on Nostr: So, I'll try to give a flavour of what's going on. You've probably heard about the ...

So, I'll try to give a flavour of what's going on. You've probably heard about the solar activity cycle. The Sun is an active star, it has transient spots at it's surface (we informally call the study of these spots solar dermatology) and a large-scale magnetic field notably responsible for spitting out particles occasionally towards us, and also reheating the atmosphere of the Sun (the corona) at millions of degrees, while the surface itself that we see in visible light is at less than 6000 degrees (hence it's yellowish appearance).

Both the number of spots and the magnetic field oscillate with a period of 11 years (but it's not truly periodic, it's chaotic, and not all cycles have the same amplitude). The spots also follow a relatively regular pattern in their appearance, called the butterfly diagram. As the cycle evolve, they appear closer and closer to the equator, in both hemispheres.

The illustrations below are satellite images and data records appearing in a review I published in 2019.

https://arxiv.org/abs/1903.07829v2