Pulsation in pre-main sequence stars: TESS observations & models from accreting protostars

Stellar mass is clearly the most important parameter in stellar evolution, governing the entire evolution from the pre-main sequence to the final fate of the star. Despite that, our theoretical stellar models often ignore how stars have obtained their main sequence mass, although it is commonly accepted that the collapse of molecular clouds creates stellar seeds that subsequently accrete material from their surroundings. In this poster, we present calculations of the pre-main sequence evolution starting from the accreting phase. We compare these evolutionary tracks to spectroscopic parameters of young stellar objects and constrain free parameters in the accretion modelling. We investigate the pulsational instability of the calculated pre-main sequence models by calculating instability regions and comparing their positions to a sample of pre-main sequence pulsators. The latter are compiled from the literature and extended by discoveries made from TESS data. Finally, we present the first candidate M-type pulsating star discovered in TESS full-frame images.