Simultaneous Multiwavelength Flare Observations of EV Lacertae
Hamaguchi, Kenji; Barclay, Thomas; Davenport, James R. A.; Huber, Daniel; Youngblood, Allison; Schlieder, Joshua E.; Mullan, D. J.; Gizis, John E.; Colón, Knicole D.; Vega, Laura D.; Boyd, Patricia T.; Osten, Rachel A.; Quintana, Elisa V.; Gilbert, Emily A.; Paudel, Rishi R.; Tucker, Michael A.; Do, Aaron; Walkowicz, Lucianne; Silverstein, Michele; Monsue, Teresa A.
United States
Abstract
We present the first results of our ongoing project conducting simultaneous multiwavelength observations of flares on nearby active M dwarfs. We acquired data of the nearby dM3.5e star EV Lac using five different observatories: NASA's Transiting Exoplanet Survey Satellite (TESS), NASA's Neil Gehrels Swift Observatory (Swift), NASA's Neutron Interior Composition Explorer (NICER), the University of Hawaii 2.2-meter telescope (UH88), and the Las Cumbres Observatory Global Telescope (LCOGT) Network. During the ~25 days of TESS observations, we acquired three simultaneous UV/X-ray observations using Swift that total ~18 ks, 21 simultaneous epochs totaling ~98 ks of X-ray data using NICER, one observation (~3 hr) with UH88, and one observation (~3 hr) with LCOGT. We identified 56 flares in the TESS light curve with estimated energies in the range log ET (erg) = (30.5-33.2), nine flares in the Swift UVM2 light curve with estimated energies in the range log EUV (erg) = (29.3-31.1), 14 flares in the NICER light curve with estimated minimum energies in the range log EN (erg) = (30.5-32.3), and 1 flare in the LCOGT light curve with log EL (erg) = 31.6. We find that the flare frequency distributions (FFDs) of TESS and NICER flares have comparable slopes, βT = -0.67 ± 0.09 and βN = - 0.65 ± 0.19, and the FFD of UVOT flares has a shallower slope (βU = -0.38 ± 0.13). Furthermore, we do not find conclusive evidence for either the first ionization potential (FIP) or the inverse FIP effect during coronal flares on EV Lac.