Mounting evidence suggests that many supernova (SN) progenitors exhibit outbursts and/or enhanced mass loss in the years preceding the SN. Such mass loss could drastically alter the appearance of both…

This is a $458,102.88 grant awarded by NASA's Shared Services Center to the California Institute of Technology (Caltech) for a research project on the effects of wave-driven outbursts and mass loss in supernova progenitors. The research aims to quantify the observable impacts on progenitor properties, shock breakouts, and supernova light curves, which are crucial for interpreting data from NASA missions like Hubble, GALEX/Swift, Kepler/K2, and TESS/WFIRST. Caltech, a private research university, is a frequent recipient of NASA and DoD prime contracts and subcontracts for scientific research, engineering, and technical services, with over $500 million in prime awards over the past 5 years. This grant supports Caltech's expertise in areas like astrophysics, materials science, and scientific computing, which are aligned with the research goals of federal funding agencies.

Mounting evidence suggests that many supernova (SN) progenitors exhibit outbursts and/or enhanced mass loss in the years preceding the SN. Such mass loss could drastically alter the appearance of both the progenitor and the subsequent SN, with significant impact on the interpretation of data collected by several NASA missions. Pre-SN progenitor variability can alter the appearance of progenitors imaged by HST, impacting the inferred progenitor properties. Additionally, mass loss preceding the SN can completely change the shock breakout signature in UV/x-RAY bands, greatly affecting shock breakouts detected by galex/swift. Third, mass loss in the final years of stellar evolution significantly impacts early SN light curves such as those being measured by kepler/K2 and (in the near future) tess/wfirst. A compelling mechanism for pre-SN outbursts is energy transport via gravity/acoustic waves within massive star SN progenitors. Preliminary investigations (quataert ET AL. 2012,2016, fuller 2017) have shown that waves excited by core convection during late-stage nuclear burning can carry large amounts of energy into the envelopes of progenitor STARS, expelling some mass and causing pre-SN progenitor variability. While encouraging, these investigations have employed many simplifications that must be improved for robust predictions of pre-SN outbursts. Additionally, these works have only investigated a very small sub-sample of SN progenitors, and they must be extended to the diverse population of STARS approaching core-collapse (e.g., hydrogen-poor STARS, very massive STARS, merger products, tight binaries, electron-capture SN progenitors, etc.) in order to understand wave heating effects for different types of SNE. We propose to quantify the observable effects of wave-driven outbursts and mass loss using mesa stellar evolution calculations incorporating wave energy transport and hydrodynamics. These models will predict the evolution of stellar structures, surface temperatures, luminosities, mass loss rates, wind speeds, and CSM density profiles. We will thus predict progenitor temperature/ luminosity as a function of stellar mass and time before explosion, which we will compare to HST progenitor data. We will then use our circumstellar density profiles to predict shock breakout signals for comparison with galex/swift data. Next, using our model stellar structures and wind density profiles, we will model SN light curves for comparison with kepler/tess data. As the number of well observed SN grows during upcoming surveys, our theoretical work will be vital for interpretation of this data, allowing US to determine which affects can (or cannot) be ascribed to wave energy transport within the progenitor. This will be crucial to understanding the late phases of massive star evolution, and the connection between the diverse population of core-collapse SNE and their stellar progenitors.