Every Datapoint Counts: Stellar Flares as a Case Study of Atmosphere Aided Studies of Transients in the LSST Era

Riley Clarke

Due to their short timescale, stellar flares are a challenging target for the most modern synoptic sky surveys. Nevertheless, wide-field surveys such as the Zwicky Transient Facility and Pan-STARRS provide an opportunity to collect ensembles of flare measurements from millions of stars across large areas of the sky. The upcoming Vera C. Rubin Legacy Survey of Space and Time, a project designed to collect more data than any precursor survey, is unlikely to detect flares with more than one datapoint in its main survey. We developed a methodology to enable LSST studies of stellar flares, with a focus on flare temperature and temperature evolution, which remain poorly constrained compared to flare morphology. Leveraging the exquisite image quality and sensitivity expected from the Rubin system, Differential Chromatic Refraction can be used to constrain flare temperature from a single-epoch detection, which will enable statistical studies of flare temperature evolution using the unprecedentedly high volume of data produced by Rubin over the 10-year LSST. Obtaining these statistics will constrain models of the physical processes behind flare emission as well as the relationship between flare parameters (e.g. temperature, duration, energy) and stellar parameters (e.g. spectral type, rotation, magnetic field). We model the refraction effect as a function of the atmospheric column density, photometric filter, and temperature of the flare, and show that flare temperatures at or above ∼10,000K can be constrained by a single g-band observation at airmass 1.2, given the minimum specified requirement on single-visit absolute astrometric accuracy of LSST. Having failed to measure flare DCR in LSST precursor surveys, we make recommendations on survey design and data products that enable these studies in future surveys, including the LSST.


This poster will be displayed on Wednesday and Thursday.


Career Stage: 
Grad Student