TITLE: GCN CIRCULAR NUMBER: 15814 SUBJECT: GRB 140209A: Swift-BAT Spectral lag analysis DATE: 14/02/10 13:53:26 GMT FROM: Scott Barthelmy at NASA/GSFC J. Norris (BSU), S. D. Barthelmy (GSFC), A. Lien (GSFC), C. Markwardt (GSFC), T. Sakamoto (AGU), N. Gehrels (GSFC) report: We report the spectral lag analysis for GRB 140209A (GCN Circ. 15808 & 15812) based on the BAT data. Using 4-ms binned light curve, the spectral lag for the 25-50 keV to 100-350 keV bands is 28 (+10/-7) ms, and +34 (+8/-5) ms for the 15-25 keV to 50-100 keV bands. These lag values are consistant with a Long GRB. Further, the extended emission is both shorter than the typical extended eimssion of a Short GRB, and its shape is exponential in decay instead of more flat-like. And lastly, there is pecursor emission. The lag for the precursor in the 15-25 keV to 50-100 keV bands is 150 (+36/-30) ms.