IA/U.Porto Cookie Seminar - Intermediate-mass stars as astrophysical laboratories - 17 fevereiro 2016
Stellar Astrophysics Centre, Aarhus University
The A and F type stars occupy a region in the HRD where several physical processes occur: it is in the classical instability strip where the transition between deep and efficient to shallow convective envelopes takes place. Because convection has an impact not only on pulsational stability but also on stellar evolution, activity, transport of angular momentum, etc., it is of great interest to understand how this transition takes place. Theoretical models predicted that the convection in the outer layers of delta Scuti stars is still efficient enough to excite solar-like oscillations. The Kepler target, HD 187547, was the first delta Scuti star to suggest that solar-like oscillations are indeed present in this type of pulsators. Interestingly, it was also identified to be a chemically peculiar Am star. Additional data, however, revealed that this target is even more complicated than expected and that an additional mechanism driving oscillations in A and F type stars is at work.
17 de fevereiro de 2016 | 13:15