A very unusual "fluxtube" from the Sun

Caption originale NASA, da "NASA - Picture of the Day" dell'11 Gennaio 1999: "The Earth's orbit is not a perfect, sun-centered circle. At aphelion, the most distant point in Earth's orbit, the Sun is 150 MKMs away and at perihelion, the closest point, Earth approaches the Sun to within about 147 MKMs. While aphelion occurs in July, perihelion for planet Earth comes in January. In fact, inhabitants of the Northern Hemisphere, particularly those wearily weathering winter storms, may be surprised to learn that Earth reached its closest point to the Sun on early January, usually the coldest month of the year. This false-color picture recorded near perihelion is from the earth-orbiting Yohkoh Solar Observatory. It shows an increasingly active Sun in the light of X-rays. A negative color scheme is used, darker colors representing more intense X-ray light". Da notare che il commento NASA non menziona nè spiega - guarda caso... - il dettaglio più intrigante dell'immagine: il "tubo" di plasma e di gas...