The next Colloquium of the Astronomical Observatory will be held on Wednesday, December 6, at 13h in the Library.
Speaker: Ivan Živanović, Astronomical Observatory
Topic: Studies of Solar activity using satellite data
Resume:
In the first part, we will present research on the speed of differential rotation of small-scale magnetic structures (faculae) on the quiet Sun. The periods of p2p artifacts are used as a measure of time. The depth of supergranular cells can be diagnosed by comparing the obtained by comparing the speeds of differential rotation of small-scale magnetic structures with the angular rotation rates determined by helioseismology.
In the second part, we will describe the work on establishing the radial profile of the vertical magnetic field in sunspots, both for individual spots and for spots in bipolar groups. Comparison of the obtained profiles shows a significant difference.
The third part will be dedicated to the study of dissipation of solar spots. In the model of the dissipation of the magnetic field of the solar spot through a thin boundary layer of the current tube, the effect of slowing down the rate of dissipation in spots with a small umbra should occur. This effect is confirmed by SOHO data.
In the last, fourth part, we will describe the phenomenon of saturation of the effect of convection suppression by strong vertical magnetic field in sunspots. This effect occurs due to the low temperature in the solar spot umbra. The value of the magnetic field strength at which the effect of saturation of convection suppression occurs has been found. Sunspots with strong vertical magnetic fields were selected for the study. The magnetic field in flares is weaker, there is no saturation in them, but even there, the relationship between brightness and magnetic field is revealed in the study of long-period oscillations.
The talk will be recorded and posted on the Observatory's Youtube channel.
