A study of flares on EV Lacertae using simultaneous multi-wavelength data

We present the first results from our large program studying nearby active flaring M dwarfs using simultaneous multi-wavelength datasets. We focus on the flaring M dwarf EV Lac, which has been known as a flare star for at least 65 years. We acquired data of EV Lac using 5 different observatories: NASA's TESS mission, NASA's Neil Gehrels Swift Observatory ($Swift$), NASA's Neutron Interior Composition Explorer (NICER) and two ground based telescopes (University of Hawaii 2.2-m (UH88) and Las Cumbres Observatory Global Telescope (LCOGT) Network), to span a comprehensive, simultaneous wavelength coverage of flaring events. We identified 56 flares in the TESS light curve, 9 flares in the $Swift$ $UVM2$ light curve, 14 flares in the NICER X-ray light curve, and 1 flare in the LCOGT light curve. However, we did not identify flares in the $Swift$ XRT light curve or UH88 spectrum. We find that the FFDs of TESS and NICER flares have comparable slopes, $\beta_{T}$ = -0.67$\pm$0.09 and $\beta_{N}$ = -0.65$\pm$0.19, and that the FFD of UVOT flares has a shallower slope ($\beta_{U}$ = -0.38$\pm$0.13). Our results will be useful to model and estimate the impacts of strong flares on the atmospheres of planets orbiting M dwarfs.