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!
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 19.5 nm.
We see an MDI/SOHO image showing the magnetic field strengths: 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!
The high energy proton fluxes all have exceeded the threshold of 10 pfu, indicating the flare was directed to the Earth. This graph is made with data measured by the GOES spacecraft.
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.
The SIDC received a number of pictures from aurora as observed in Belgium:
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
A press release on the X10 flare (30/10) has been written and is available in Nederlands and Français.
