Astrophysics & Particle Physics-APPC 2026

Time-Domain Astronomy is concerned with the study of the dynamic universe by watching celestial objects and cosmic events change over minutes, hours, days, or years. In contrast to static sky surveys, this astronomy emphasizes variability and transience, monitoring events that emerge and often disappear rapidly.Transient events like supernovae, kilonovae, gamma-ray bursts (GRBs), and fast radio bursts (FRBs) expose the violent and energetic processes that mold the cosmos. For instance, supernovae enrich galaxies with heavy elements, and kilonovae in neutron star mergers create gold and platinum.

Time-domain astronomy captures the short-lived signals, allowing scientists to trace the source of cosmic phenomena.A second significant area is the observation of variable stars, such as Cepheids and RR Lyrae, which pulsate in periodic brightness variations. These stars act as cosmic distance beacons, necessary for mapping the scale of the universe. Equally, exoplanet transits, where planets cross in front of their parent stars, are identified through observing minute drops in brightness over time. Large telescopes and surveys have transformed this endeavor. Surveys such as the Zwicky Transient Facility (ZTF) and the future Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) offer wide-field, high-cadence monitoring of the sky, observing thousands of transients each night. Coupled with rapid-response follow-up by telescopes globally, these sites make possible real-time investigation of the evolving universe.

Time-domain astronomy also intersects with multi-messenger astronomy, since most transients emit not just light but also gravitational waves, neutrinos, or cosmic rays. Simultaneous detections across messengers provide a full view of astrophysical events.Time-Domain Astronomy brings the universe to life, repositioning astronomy from static sky maps to a dynamic science of real-time cosmic narrative.