Date: 31 Oct 2003
Copyright: SOHO/MDI (ESA & NASA)

This movie shows the Sun's disk between 20 and 31 October 2003, as observed by the Michelson Doppler Imager (MDI) on board SOHO. The sunspot group of active region 10486 is the second group of sunspots that appears in the movie. It first comes into view at the Sun's limb in the night from 22 to 23 October, just below the Sun's equator. As the Sun rotates, the active region crosses the Sun's disk.

Active region 10486, which was already under close scrutiny by several instruments on board SOHO and other satellites, as well as numerous ground observatories, started up a spectacular two-part show in the morning on Tuesday 28 October 2003.

An X 17.2 flare, the second largest flare observed by SOHO, set off a strong high energy proton event and a fast-moving Coronal Mass Ejection (CME), hitting the Earth early on Wednesday 29 October. The encore came on Wednesday afternoon, when an X 10.0 flare from the same active region set off another round of particles and another fast-moving CME.

See the related videos for movies of the two flares and of the CMEs.