Dr. John Barentine FRAS on Nostr: Today's H-alpha #Sun at 17:00 UTC. Chromospheric activity has calmed down since ...

Today's H-alpha #Sun at 17:00 UTC. Chromospheric activity has calmed down since yesterday, but the limb prominences continue to impress. The tall one standing nearly straight up on the NNE limb has a linear extent about 6.5 times the diameter of the Earth. #Astronomy #Solar #Cycle25