Calendar of Events

Speaker: Lindsey Kwok, Northwestern University/CIERA

Abstract: White dwarfs — the dense embers of dead stars — sometimes end their lives in powerful thermonuclear explosions known as type Ia supernovae (SN Ia). These events are essential for measuring the expansion of the universe, tracing the origin of the elements, and testing physics under extreme conditions, yet the details of how they ignite and burn remain poorly understood. The James Webb Space Telescope (JWST) provides an unprecedented mid-infrared view of these explosions. This wavelength range cuts through the blended spectral features that dominate optical light. It reveals isolated atomic lines, new signatures of dust and molecules, and the structure of the inner layers. These distinct diagnostics are transforming our understanding of how white dwarfs explode. I will highlight results from the first JWST spectra of both normal and peculiar white-dwarf explosions—ranging from subsonic-to-supersonic burning, through violent white-dwarf mergers, to weak explosions that leave behind remnants. Looking forward, I will showcase recent and upcoming observations and discuss how JWST is taking us further than ever before in reconstructing the exploded star from its spectral fingerprints.

Host: Saurabh Jha