This webinar features talks by two astronomy researchers:
First, Trevor Dorn-Wallenstein, "Solving the Red Supergiant Problem with a New Class of Pulsators." Massive stars drive the radiative, chemical, and kinematic evolution of their host galaxies. Despite the importance of these stars, the physical factors that govern their progression through their exotic evolved states are poorly understood. In particular, there is a mismatch between the masses of stars we expect to explode as supernovae, and the red supergiant stars we have witnessed undergoing this cataclysmic event—a discrepancy known as the red supergiant problem. One potential solution? If the most massive and luminous red supergiants shed enough of their envelopes before the ends of their lives, they explode as yellow or blue supergiants instead. Discovering the lowest mass star that undergoes this phenomenon would place stringent constraints on the evolution and final fates of massive stars. Dorn-Wallenstein will discuss the discovery of a new class of pulsators called “fast yellow pulsating supergiants” (FYPS) that may be genuine post-red supergiant objects, as well as the scientific avenues that this class may let us explore. He will also demonstrate how observations from AAVSO observers can enable similar discoveries.
Following is Dr. Burçin Mutlu-Pakdil, "The Faintest and Smallest Galaxies." Such galaxies around the Milky Way are the most ancient, metal-poor, and dark-matter-dominated systems known. These extreme objects offer unique access to small scales where the stellar and dark matter content can be studied simultaneously and hold the promise of major breakthroughs in understanding the nature of dark matter, and a more complete picture of galaxy formation. Thus, their discovery and characterization are among the most important goals in the field. Dr. Mutlu-Pakdil will share ongoing observations to detect these systems, and upcoming advances in the era of deep and wide imaging instrumentation.