Characterization of the NUV and optical emission and temperature of flares from Ross 733 with <i>Swift</i> and <i>TESS</i>

ABSTRACT We present the results of a coordinated campaign to simultaneously observe M star binary Ross 733 in optical and near-ultraviolet (NUV) with TESS Swift, respectively. observed two flares Swift NUV light curve. One these was decay phase flare that also detected other only NUV. used curve measure white-light rate 733, calculate system an energy 1033 erg once every 1.5 d. our simultaneous observations pseudo-continuum temperature $7340^{+810}_{-900}$ K during decay. test predictions 9000 blackbody model, find it underestimates number we detect discuss reasons for this attribute unaccounted contributions from emission lines continuum temperatures above K. how additional are required break degeneracy between future multiwavelength campaigns.