X-ray flare of HOPS 383. Panel a: sky position of the X-ray events detected during the Chandra observation on 2017 December 13. The cyan cross and circle are the X-ray position and positional error of HOPS 383, respectively. The dashed and solid contours encompass 90% (position determination) and 96% (spectrum extraction) of 1.49 keV point source emission, respectively. The diamonds mark the events from the 6.4 keV emission line. Panel b: event energy versus time of arrival. The gray stripe is centered at 6.4 keV and corresponds to a confidence interval of 54% centered at this emission line observed with ACIS-I (inset). Panel c: cumulative counts and various smoothed light curves. The dashed curve is the mirrored rise phase of the red curve. Panels b and c: the vertical dotted line at ∼6.7 h marks an exposure gap of 3.1 s.