Shanghai Astronomical Observatory Astrophysics Colloquium

Time：3:00pm June 2th (Thursday)

Zoom ID：813 9781 8678，password：6360

Speaker：Dr. Kareem El-Badry（Harvard University）

Title：Better together: binary stars as probes of star formation and evolution

Abstract：Binary stars are foundational to modern astrophysics. They underpin precision measurements of stellar structure, age, and composition; they provide the most stringent tests of general relativity, they make possible the study of faint and rare objects such as black holes and neutron stars, and they are the progenitors of gravitational wave sources. The components of binaries often interact, dramatically changing their evolution and giving rise to a spectacular zoo of astrophysical phenomenology. Large-scale stellar surveys such as Gaia, TESS, and SDSS-V are transforming the binary field, making possible both comprehensive population demographics and the discovery of rare objects. I will discuss new insights gleaned from surveys in recent years, including the creation of stripped-envelope stars following binary mass transfer, the formation of equal-mass "twin" binaries in circumbinary disks, and the search for quiescent stellar-mass black holes. I will pay particular attention to the ways in which binary interactions open up new stellar evolution pathways, filling in regions of the HR diagram that are classically empty. 

Bio: Kareem is a postdoc at the Harvard Institute for Theory and Computation who recently completed his PhD at UC Berkeley. He has broad research interests including stellar populations, stellar feedback in galaxy formation, and globular clusters. His recent work is focused on binary stars, using a mix of observations and theory.