Forum E.R.A.

Da qualche giorno, l'intensa attività della nostra Stella, rende sorprendente anche il nostro amato contesto radiantistico. Si passa dalla piacevolissima propagazione di ieri sera (ottimi i DX in bande basse), al radio black out di stanotte alle 4 circa, in cui l'HF ha crashato per circa 10 minuti.
Interessante è l'osservazione a luce bianca, che rende l'idea di enormità delle macchie solari

notizia fresca:

First Moments of a Solar Flare in Different Wavelengths of Light

On Feb. 24, 2014, the sun emitted a significant solar flare, peaking at 7:49 p.m. EST. NASA's Solar Dynamics Observatory (SDO), which keeps a constant watch on the sun, captured images of the event. These SDO images from 7:25 p.m. EST on Feb. 24 show the first moments of this X-class flare in different wavelengths of light -- seen as the bright spot that appears on the left limb of the sun. Hot solar material can be seen hovering above the active region in the sun's atmosphere, the corona.
Solar flares are powerful bursts of radiation, appearing as giant flashes of light in the SDO images. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel.

http://www.nasa.gov/content/first-momen ... -of-light/