Μάθημα : Ενημέρωση φοιτητών κατεύθυνσης Αστροφυσικής

Speaker: Prof. Ylva Götberg, Institute of Science and Technology Austria (ISTA)

Title: Stars stripped in binaries: from theory to observation

Image Credit: Navid Marvi, courtesy of the Observatories of the Carnegie Institution for Science

Abstract: A third of all massive stars are predicted to lose their hydrogen-rich envelope through mass transfer or common envelope ejection initiated by a binary companion star. As a result, the hot and compact helium core is exposed. These "stripped stars" are the direct progenitors of hydrogen-poor supernovae and merging binary neutron stars, but they are also so hot that they should boost the ionizing output from bursty star-forming galaxies. Despite their importance, stripped stars remained, until recently, observationally unconfirmed since their predicted existence over half a century ago. We found the first set of stripped stars by combining ultraviolet and optical photometry with follow-up spectroscopy in the Magellanic Clouds. By fitting their spectra with a new grid of models, we could measure stellar properties and thus confirm that the predictions from binary evolution models are broadly consistent with observed stripped stars.

Abstract: