Cosmic Explosions and Galactic Life with Tsvi Piran (The Hebrew University of Jerusalem, Israel)

The stars that seem to us everlasting, are not eternal. Every once in a while we witness distant cosmic explosions. Dying stars explode in Supernovae, spreading essential elements for life that were synthesized deep in their cores. Kilonovae arise when compact binaries merge, producing heavier elements such as Gold and radioactive elements like Uranium, Plutonium and Thorium. A typical Supernova explosion in our Milky Way Galaxy can be seen during daylight, but it is not harmful. Some Supernova and Kilonova harbor powerful jets that drive dangerous Gamma-Rays Bursts. If sufficiently nearby these could destroy life. The higher rate of Gamma-Ray Bursts in the inner regions of the Milky Way delineate the habitable Galactic zone, possibly explaining the Fermi paradox.

Tsvi Piran is the Schwarzmann chair for theoretical physics at the Hebrew University of Jerusalem. Piran graduated in 1976 from the Hebrew University and was a research fellow at Oxford, UT Austin and the Institute for Advanced Study in Princeton. He was a visiting Professor at Harvard, Columbia and NYU and a distinguished Moore Scholar at Caltech. Piran’s research spans numerous aspects in theoretical astrophysics ranging from inflation at the early universe to the mysterious gamma-ray bursts. He has published more than 500 scientific papers and is one of the most highly cited astrophysicists. Piran received the Lagrange award from the Lagrange institute in Paris in 2015 and the EMET prize from the Israeli prime minister’s office in 2019.

Webinar was recorded on February 10, 2022