Using ALMA to Detect Millimeter Flaring Emission from Proxima Centauri

Understanding the physics of flares on cool M dwarf stars like Proxima Centauri, which hosts the closest exoplanetary system to Earth, will help us determine how flaring activity affects the atmospheres and potential habitability of orbiting planets. I present a thorough, millimeter analysis of stellar flaring activity on Proxima Centauri using the Atacama Large Millimeter/submillimeter Array (ALMA). I have created automatic pipelines to probe ~40 hours of ALMA observations for flaring activity, enabling the detection of the faint flares that occur most frequently. Using these pipelines, I have explored flare characteristics including luminosity, spectral index, and polarization, and created the first Flare Frequency Distribution (FFD) at millimeter wavelengths. Interestingly, this work has provided significant evidence that stellar flares at millimeter wavelengths can be shorter in duration than previously thought. My analysis revealed an exceptionally bright flare on April 29, 2019, where the star brightened by a factor of ~780. These ALMA observations are part of a larger multi-wavelength campaign spanning millimeter to X-ray wavelengths. For this large flaring event, I will use these simultaneous observations to investigate whether flaring emission is correlated across the electromagnetic spectrum.