Third Very large X-ray burst in less than one week !!!

Press release on the X10 flare (30/10): Nederlands, Français

Press release on the X17 flare (29/10): Nederlands, Français

The 'green' sun is an image taken by EIT on SOHO. The active region which produced the X-flare is bright because it is emitting strongly in 195 Å. You can click on the figure to see a movie.

We see an MDI/SOHO image showing the magnetic fieldstrengths: black and white spots denote areas of intense (opposite) magnetic flux. The biggest spot in the middle is the sunspot group that caused the three X-ray flares. It has a size which is 15 times the size of the earth, the biggest group of this solar cycle! You can click on the picture to enlarge it.

Three major flares from the same sunspot group

For the third time this week a major flare erupted from the same sunspot group (Catania 70, NOAA 0486). This time the flare reached an X-ray level of X10, peaking at 20:49 UT on 29/10. Shortly after a CME (Coronal Mass Ejection) was visible in LASCO C2 at 20:54 UT. It was travelling direct to the earth with an estimated speed of about 1950 km/s. This is slightly slower than the previous one (2125 km/s) but still, this is very fast for a CME! The geomagnetic storm related to the X10 started last evening at about 6 UT. It is still going on. We already were informed that the GPS measurements were highly disturbed. As a bonus, nice auroras have been seen!

Bocholt (Belgium); photo: Chris Janssen 30/10,
Volkssterrenwacht Genk

Limburg (Belgium); photo: Philippe Mollet 30/10, Volkssterrenwacht MIRA Grimbergen

Waremme (Belgium); photo: Jean-Marie Maillard 30/10,
Société Astronomique de Liège

The high energy proton fluxes all have exceeded the threshold of 10, indicating the flare was directed to the earth. This graph is made with data measured by the GOES spacecraft.

Click on the figures for a larger version.

Scientists classify solar flares according to their x-ray brightness in the wavelength range 1 to 8 Angstroms. We have the A, B, C, M and X level. X-class flares are big; they are major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. These measurements are made by Goes, a geostationary satellite.