Solar Cycle 25 - the Solar Magnetic Field from Solar Minimum to Pole Flip
One advantage of long-lived missions like Solar Dynamics Observatory (SDO) is the ability to see slow but significant changes over long periods of time. This view from SDO's Helioseismic and Magnetic Imager (HMI) shows the evolution of sunspots on the solar disk starting from solar minimum (around December 2019) and into the maximum solar activity phase. The video ends in September 2024, however this maximum phase is expected to continue into 2025. The peak solar maximum of this solar cycle has not yet been identified. In the first video, the images are sampled uniformly, about every six hours over this time period. Starting at solar minimum, we observe very little detail on the Sun, but for an occasional sunspot. As the Sun evolves further into the cycle, sunspots appear more frequently, and larger.
Evolution of Solar Cycle 25 as seen in the SDO/HMI instrument from solar minimum (December 2019) to the solar maximum phase at 6 hour intervals. The view ends in September 2024. HMI (Helioseismic and Magnetic Imager) views the solar photosphere in wavelengths of visible light so we see sunspots and faculae. Note there are two brief partial lunar transits over the Sun's disk across the upper right limb, one on January 13, 2021 and the other on May 20, 2023.
