Unveiling the spectacular over 24 hour flare of star CD-36 3202

Abstract

We studied the light curve of the star CD-36 3202, which was observed by TESS for the presence of stellar spots and to analyze the rotationally modulated flare that took place on TBJD (TESS Barycentric Julian Date) 1486.93. Our main aims are to model the light curve of this flare and to estimate its location regarding stellar spots. The flare lasted approximately 27$\,$h. Using our new tool findinc\_mc we managed to estimate the inclination angle of the star to $70^ With BASSMAN we modeled the light curve of the CD-36 3202 and estimated that three spots are present on its surface. The mean temperature of the spots was about $4000 765\,$K, and their total area amounted to $11.61<!PCT!> on average. We created a new tool, named MFUEA to model rotationally modulated flares, and used it to estimate the latitude of the long-duration flare event (LDE), finding $69^ \,$deg. Our estimation of the flare location is the first recreation of the exact position of a flare in relation to starspots. The flare is placed 12$^ from the center of the coolest spot. This means that the flare is related to the magnetic processes above the active region represented by the spot. Removing the effects of rotational modulation from the flare light curve allowed us to correct the estimation of bolometric energy released during the event from $(1.15 \,$erg to $(3.99 \,$erg.