Speaker
Description
Large magnetic reconnection–driven flares are ubiquitous in young, pre-main-sequence stars, yet their impact on the chemistry of protoplanetary discs remains almost entirely unconstrained observationally. Chemical evolution at disc scales, where grains form, migrate, and assemble into future planets, is expected to respond rapidly to flare-driven X-ray, UV, and suprathermal particle irradiation. However, the stochastic nature of flares and the difficulty of coordinating simultaneous X-ray and infrared observations have so far prevented direct empirical tests.
I will show how thermo-chemical modelling with ProDiMo predicts that these flares can boost key molecular tracers (e.g. OH, CO, and CO₂) by tens to hundreds of percent on sub-day timescales, a regime uniquely accessible to JWST.
I will then present a joint Chandra+JWST program, scheduled for February 2026, designed to test these predictions by capturing, for the first time, the time-dependent chemical response of dozens of protoplanetary discs to large X-ray flares in the Orion Nebula Cluster.
By combining X-ray flare diagnostics, high-resolution infrared line variability, and forward modeling, I will present how this study will provide the first empirical constraints on flare-driven disc chemistry and ionization, with implications for disc evolution, accretion physics, and the initial chemical inventory of forming planets.
| Stream | Science or Engineering |
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