On 5 May Barkha Yakub Bale successfully defended her PhD thesis “Abundances of Chemical Elements in Magnetically Active Stars”. Supervisor – Prof. (HP) Gražina Tautvaišienė.
Her thesis investigates the influence of magnetic activity on the chemical composition and internal mixing processes in stars. After conducting spectroscopic analysis of more than 50 magnetically active RS Canum Venaticorum (RS CVn) stars, observed at Molėtai Astronomical Observatory of the Institute of Theoretical Physics and Astronomy, and 12 exploding stars, observed at the Nordic Optical Telescope, the researcher investigated whether the chemical composition of such stars matches the predictions of stellar evolution models.
”The results show that in magnetically active stars, internal mixing processes can occur earlier than expected, as indicated by low carbon isotope ratios and unusual lithium abundances. These findings suggest that magnetic activity plays a key role in modifying the internal structure and evolution of stars. In contrast, the chemical abundances of eruptive stars remainconsistent with predictions from standard stellar evolution, implying that their surface activity does not lead to significant modification of their chemical composition. These findings demonstrate that magnetic activity plays a key role in altering the timing and efficiency of internal mixing in evolved stars, providing new insights into stellar evolution and chemical enrichment in the Galaxy,” explains Dr Bale.
