04.10.2016

Ondrej Pejcha (Princeton University, USA)

Death Throes of Binary Stars: Cool and Luminous Transients

STRESZCZENIE The discovery of a contact binary with rapidly decreasing orbital period followed by an outburst in V1309 Sco established a connection between catastrophic phases of binary star evolution and a group of transients characterized by their red color and the luminosity in the gap between classical novae and supernovae. To utilize the wealth of information gathered on these transients, we explore the dynamics of outflows from mass-losing binary stars using smoothed particle radiation-hydrodynamic simulations with realistic equation of state and opacities. We identify several distinct outflow regimes as a function of the parameters of the perishing binary star and make the connection with the properties of the observed transients focusing specifically on modeling the pre-maximum OGLE data of V1309 Sco.

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O PRELEGENCIE I did my undergraduate work at Charles University in Prague working on the theory of finite-source effect in two-point-mass microlensing, which I followed with PhD at The Ohio State University (2008-2013). After that I've been postdoc at Princeton University as a Hubble Fellow (2013-2016) and subsequently Lyman Spitzer Fellow. I have worked on the explosion mechanism of core-collapse supernovae and its connection to observations (explosion condition, compact remnant masses, explosion energies etc), but I also pursued projects on modeling light curves and velocities of Cepheids and Type II-Plateau supernovae, classical novae, structure of LMC, and observations and theory of quadruple binary star systems. My recent interest are stellar mergers and the associated transients.