Speaker: Monika Jurkovic (Astronomical Observatory Belgrade)
Title: Pulsating stars: From their individual behaviors through their position in the Milky Way to their period-luminosity relations
Abstract:
Pulsating stars can be found in the instability strip (IS) of the Herztsprung-Russell diagram. The common feature for all of them is that they pulsate, changing their luminosity and radius in the process. What separates the different types of pulsating stars is in which stage of their evolution they were when crossing the IS. They can be young, intermediate stars (such as classical Cepheids, for example) or old, low mass stars (RR Lyrae or type II Cepheids). With the unprecedented precision of astrometric, photometric and spectrophotometric mapping of the stars in the Milky Way using the Gaia space telescope, galactoarcheology of pulsating stars became possible. We will illustrate this on the sample of type II Cepheids by showing their three dimensional orbits from the time they were created to the present day. All pulsating stars form period-luminosity (PL) relations. The PL relation of the classical Cepheids is the stepping stone of the extragalactic distance ladder. We will discuss how other type of pulsating stars can be used too for distance estimation, with the current observational situation, and with new facilities, such as E-ELT and LSST.
Room: Zoom videoconference (contact justin.feng@tecnico.ulisboa.pt for URL)