caa a22 4500 445346094 CHVBK 20180317142829.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s11207-011-9749-y doi (NATIONALLICENCE)springer-10.1007/s11207-011-9749-y Pishkalo Mykola Astronomical Observatory of Kyiv National Taras Shevchenko University, 3, Observatorna vul., 04053, Kyiv, Ukraine aut Flattening Index of the Solar Corona and the Solar Cycle [Elektronische Daten] [Mykola Pishkalo] The photometrical flattening index of the solar corona a+b is defined according to Ludendorff. In this paper we have investigated how the flattening index varies with respect to the phase of solar activity and the sunspot number. We have compiled 170 values of the flattening index using the data on 60 total solar eclipses from 1851 to 2010. We have found that the flattening index takes values from 0 to 0.4, and is anticorrelated with solar activity. The value of the flattening index at the beginning of solar cycle 24 was used as a precursor to forecast the amplitude of the cycle. It was found that the amplitude of solar cycle 24 will be about 95 in terms of the smoothed monthly sunspot numbers. Springer Science+Business Media B.V., 2011 Solar corona nationallicence Solar cycle nationallicence Solar Physics Springer Netherlands 270/1(2011-05-01), 347-363 0038-0938 270:1<347 2011 270 11207 https://doi.org/10.1007/s11207-011-9749-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9749-y text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Pishkalo Mykola Astronomical Observatory of Kyiv National Taras Shevchenko University, 3, Observatorna vul., 04053, Kyiv, Ukraine aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 270/1(2011-05-01), 347-363 0038-0938 270:1<347 2011 270 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer