According to the Agency of Scientific Information, the Institute of Physics named after P. Lebedev summed up the results of space experiments held in 1994-2009 within the framework of the Koronas program (complex orbital circumterrestrial solar activity observations) effected by the RAS that envisaged launching of 3 new sun-oriented satellites to the orbit.
Extraatmospheric studies of the nearest star has been carried out for 50 years. On the initiative of the well-known Soviet physicist Sergei Mandelshtam, Corresponding Member of the USSR AS from 1979, the second artificial satellite of the Earth* launched on November 3, 1957, was furnished with the device registering X-ray short wave radiation. The equipment designed at the Laboratory of X-Ray Astronomy of the Sun, FIAN, registered the first monochromatic pictures of the disc and the corona attached to it in the X-ray spectrum with high spatial and temporal resolution. As a result, scientists discovered a new class of hot plasma structures with sizes varying from tens to hundreds of thousands of kilometers and the temperature exceeding 5 mln пїЅC. They also ascertained some other scientific data: the temperature of the external boundary layer of the Sun called the photosphere is about 6,000 пїЅC; while moving away from the surface it drops to about 4,000 пїЅC, but then suddenly rises. In a thin, the so-called transitional layer (in a solar scale), where the plasma density reduces by some orders the temperature reaches 1.5 mln пїЅC.
"Why is the corona hot? We do not know,"--Alexander Urnov, a leading research assistant of the Spectroscropy Department, FIAN, tells us. "An enormous amount of energy is reserved in the magnetic field of various mag-netoplasma structures. Explanation of the mechanism
* See: Yu. Markov, "Breakthrough Into Cosmos--Our Glory and Pride", Science in Russia, No. 2, 2007.--Ed.
of its isolation and transformation into other forms (accelerated particles ... Read more