Overview
- A peer-reviewed paper from the Max‑Planck Institute published Thursday finds an empirical relationship between active-region area and bolometric flare energy and uses that link to estimate upper energy limits for historical sunspots.
- The team used NASA Solar Dynamics Observatory data from 2010–2016, comparing about 300 strong flares to the size of their active regions and then extrapolating those statistical relationships to long-term sunspot records.
- The April 1947 sunspot, which covered roughly 0.6% of the visible solar disk, is large enough that the study says it could have produced a superflare in statistically rare cases, though no direct observations of such an event exist.
- Authors stress large uncertainties in the conversion from spot area to flare energy—estimates could shift by factors of roughly two to three—and the study does not determine how often superflares might occur.
- If a superflare did hit Earth today it could severely damage satellites, power transformers and vulnerable high-latitude undersea cables, and the paper places this risk alongside other evidence such as past isotope spikes and the smaller but well-documented Carrington storm.