The sun surprised observers on Tuesday with three M-class solar flares, breaking a long quiet spell.

Sunspot group AR4545 fired an M1.1 flare at 18:48 UTC on October 5. Then newcomer AR4549 unleashed an M1.4 at 6:10 UTC and an M1.8 at 8:05 UTC on October 6. Each flare caused a minor radio blackout on the sunlit side of Earth.

The GOES-19 satellite captured the action. Its instruments watch the hot plasma of solar flares in extreme ultraviolet light.

Scientists are watching AR4549 closely. The new sunspot group emerged near the centre of the sun’s disk and has grown fast. It already has the most complex magnetic structure possible, which means it could produce more M-class or even X-class flares.

The flares came just as Earth was recovering from a moderate geomagnetic storm driven by fast solar wind. That storm triggered auroras at high latitudes. With AR4549 facing Earth, more activity is possible in the coming days.