HOW THE SUN TEMPERATURE REACHES MILLIONS OF DEGREES
ISU Researchers’ Paper Published in Nature Astronomy
A joint paper by Georgian (ISU), Indian, Polish, Italian, British and American scientists on the propagation of pseudo-shocks in the solar atmosphere was published in Nature Astronomy. The phenomenon having been observed for the first time, the project is regarded a scientific breakthrough in the study of the heating of the plasma of the solar corona.
The temperature of the upper solar atmosphere (corona) reaches million degrees, 100 times exceeding the temperature of the surface (photosphere). Temperature dramatically increases to an altitude of several hundred kilometres. The plasma of the solar corona would cool down without having a source of heating. The latter has not been established by now, which is a major issue in the study of the solar corona heating. Energy presumably moves from the lower layers along the magnetic field heating the corona plasma. However, the process of transporting energy has not been observed yet.
Pseudo-shocks around a sunspot (large-scale magnetic structures in the solar photosphere) were observed for the first time jointly by the NASA space missions Interface Region Imaging Spectrometer (IRIS) and Solar Dynamics Observatory.‘The pseudo-shocks being responsible for carrying the energy heating the solar atmosphere, their observation is a breakthrough in the study of the solar atmosphere heating, says ISU Professor Teimuraz Zaqarashvili, a co-author of the paper and researcher of the Abastumani Astrophysical Observatory. By numerical counting of equations for partially ionised plasma we modelled the observations, which is a significant breakthrough. The planned high-resolution observations will contribute to the explanation of the solar atmosphere heating enigma’.
A. K. Srivastava, K. Murawski, B. Kuzma, D. P. Wojcik, Teimuraz Zaqarashvili, M. Stangalini, Z. E. Musielak, J. G. Doyle, P. Kayshap, B. N. Dwivedi. Confined pseudo-shocks as an energy source for the active solar corona. Nature Astronomy, 10.1038/s41550-018-0590-1, 2018