RSAA Colloquia / Seminars / Feast-of-Facts: Friday, 13 October 2017, 14:30-14:50; Duffield Lecture Theatre

Daniel Faes

"Be stars - fast rotators and circumstellar disks"

Be stars are main­ sequence fast-rotating stars that display a circumstellar emission. This emission is regarded as originated from a disk, formed by episodic mass-loss from the star. I will present the current modeling efforts and recent achievements of the BeACoN group at the IAG/­USP (Brazil), which aims at understanding the rich Be phenomenology and the physical processes driving It. Based on the VDD (Viscous Decretion Disk) model and radiative transfer simulations, I will report (i) the observational campaign of the Be star Achernar over a full active phase, that started in 2013 and ended in 2016; (ii) the measurement of the Be disks viscosity from a sample in the Magellanic clouds and (iii) some predicted and observed binarity effects in these systems.