ﻻ يوجد ملخص باللغة العربية
We show in this paper that the changes of the solar diameter in response to variations of large scale magnetic fields and turbulence are not homologous. For the best current model, the variation at the photospheric level is over 1000 times larger than the variation at a depth of 5 Mm, which is about the level at which f-mode solar oscillations determine diameter variations. This model is supported by observations that indicate larger diameter changes for high degree f-modes than for low degree f-modes, since energy of the former are concentrated at shallower layers than the latter.
The solar brightness varies on timescales from minutes to decades. Determining the sources of such variations, often referred to as solar noise, is of importance for multiple reasons: a) it is the background that limits the detection of solar oscilla
In this paper, we identified the magnetic source locations of 142 quasi- homologous (QH) coronal mass ejections (CMEs), of which 121 are from solar cycle (SC) 23 and 21 from SC 24. Among those CMEs, 63% originated from the same source location as the
The measurement of the Suns diameter has been first tackled by the Greek astronomers from a geometric point of view. Their estimation of ~1800, although incorrect, was not truly called into question for several centuries. The first pioneer works for
The solar wind is a magnetized plasma and as such exhibits collective plasma behavior associated with its characteristic spatial and temporal scales. The characteristic length scales include the size of the heliosphere, the collisional mean free path
Recent observations in extreme-ultraviolet (EUV) wavelengths reveal a new late phase in some solar flares, which is seen as a second peak in warm coronal emissions ($sim3$ MK) several tens of minutes to a few hours after the soft X-ray (SXR) peak. Th