Speaker
Description
We present GalRSG, a new catalogue providing a homogeneous physical characterization of hundreds of Galactic red supergiant (RSG) stars. This dataset stems from a long-term, panchromatic, high-cadence monitoring campaign targeting the Scutum–Crux region with VST@Paranal and REM@La Silla. To derive robust parameters (such as effective temperature, extinction, luminosity, radius, mass-loss properties, and distances), we utilize MCMC-based spectral energy distribution fitting from the optical to the mid-infrared. By combining MARCS stellar atmospheres with DUSTY circumstellar dust models and applying a multidimensional kernel-density analysis to the posteriors, we ensure highly reliable parameter inference.
Our analysis reveals that roughly 50% of the sample hosts a dense circumstellar medium, while about 80% of the sources seem to be intrinsically variable. Our observed sample contains a large number of RSGs alongside a substantial population of Asymptotic Giant Branch (AGB) stars, and we will extract detailed light curves for both groups. Having such a rich, dual-population sample provides an excellent opportunity to study massive stars and core-collapse supernova (CCSN) progenitors, while directly mapping the physical and observational boundaries that separate them. In particular, some of the RSGs in our sample may actually be precursors to massive AGB stars, still residing in their core helium-burning phase. This high prevalence of dynamic circumstellar environments underscores why systematic, high-cadence monitoring is vital to separating classical stellar pulsations from genuine, pre-collapse anomalies across both populations.