Presto message sent on February 26: "An X1.1 flare erupted early this morning (start: 01h50 UT, peak: 02h03 UT, end: 02h10 UT) from Catania sunspot group 67 (NOAA active region 10564). This active region was barely visible just a few days ago but now stretches eight Earth diameters. It has a beta-gamma configuration. Continued strong flaring activity remains possible. ..."
Above an EIT-movie of the period from February 24 until March 1. Early February 26, sunspot group 67 (NOAA 10564) lightens up. At that time and that place, there is a strong radiation with wavelength of 19.5 nm, which falls in the range of the extreme ultraviolet.
Sunspot group 67 shook the Sun awake. In the x-ray plot made by the satellite GOES (picture above), we see that the background radiation started to increase from February 24 to reach the upper part of the B-level. Several C-flares where produced and suddenly the curve reached the X-class level! This was unexpected having the previous weeks in mind in which the Sun doze off. From February 10 until February 24, the background radiation was a rippled curve situated in the lower B-level. Apart from February 16 and February 22, only B-flares were registered.
At that moment of the flare, the sunspot was situated near the center of the solar disk. However, the impact of the flare on Earth was minor. First of all, there was no accompanying CME (coronal mass ejection). Secondly, there are the particles like protons and electrons thrown of the Sun in the direction of Earth. This flux is measured by ACE, a satellite in the L1 point, next to SOHO. Only the particle flux of the low energy levels rose a little. The flux of the high energy particles did not exceed the threshold, in this way we were spared from a proton event. The sudden release of energy manifested itself only in a strong increase of radiation and not in a kinetic form such like a CME or proton storm. A CME or a proton cloud is a physical entity, mass in this case, that is ejected from the Sun and moves through space. Physically speaking we say that the moving mass has kinetic energy.
The sunspot is now ready to disappear behind the west limb. The Sun is behaving again flare-quiet.
