Speaker
Description
First Name: Darejan
Last Name: Japaridze
Affiliation: ABAO & IlIAUNI
All Authors: Darejan Japaridze
Abstract: The study investigates the differential rotation of solar chromospheric Hα filaments using polynomial regression models derived from Abastumani Astrophysical Observatory data. Discrete orthogonal polynomials of up to degree 4 were employed, with model selection guided by the Akaike information criterion. The analysis demonstrates that degree 2 polynomials yield the most reliable representation of solar differential rotation. Equatorial rotation rates remained nearly constant during 1957–1993, whereas the average angular velocity—interpreted as the “rigid body” rotation rate—displayed both cyclic variability and a long-term decreasing trend. The spatio-temporal distribution of rotation rates further reveals evidence of a 22 year periodicity in the Sun’s differential rotation pattern.