Intensity variation at the flare site observed in Fermi/GBM, GOES, and IRIS SJIs. Panel a: X-ray count rates detected in two energy channels by Fermi/GBM. Panel b: GOES light curve for the B6.7 class solar flare. It shows that the flare starts at 02:02 UT and peaks at ≈02:06 UT, with small peaks corresponding to GBM peaks. Panel c: intensity light curves at the bright points in the IRIS 2832 Å SJIs. The black and blue curves are the light curves over the green and blue boxes presented in Fig. 2d, respectively. The DN signal at the flare base is integrated and divided by the total number of pixels.