Time-resolved (1 s bins) properties, with 1σ errors, of the thermonuclear X-ray burst observed from IGR J17591–2342 with AstroSat/LAXPC (see section 4.2.2). Parameter values of panels a, b, c are the same as panels c, d, e of Figure 2, respectively, and the vertical dotted lines mark the approximate maxima and minima of softness (panel a). The spectral parameter values of panels b and c were obtained by spectral fitting with the XSPEC model tbabs(bbodyrad+constant*powerlaw+gauss+gauss) and with powerlaw parameter values frozen to the pre-burst values (Section 3). In each panel, the blue best-fit model (solid line) does not include a Gaussian component for the hump, likely due to a second PRE, while the red best-fit model (solid line) includes such a component. An F-test between these two models shows the significance of the hump as likely being due to a second PRE (see Section 4.2.2). In panel c, the dotted red line is the solid red line minus its Gaussian component. Hence, a comparison between the solid and dotted red lines in panel c clearly shows the size of the blackbody temperature hump, which is likely due to a second PRE.