A 4.1 keV spectral feature in a type 1 X-ray burst from EXO 1747-214

A spectral analysis of two type 1 bursts from EXO 1747-214 detected by Exosat is presented. During the rise of the strongest burst, the spectrum display a spectral feature which is well represented by an absorption line at 4.05 + or - 0.12 keV with an equivalent width of 570 + or - 87 eV and an upper limit to the line width at 800 eV. At all other times, the spectrum is well represented by that of a single blackbody. The observed line energy is compared with those observed in other burst and the possible origins of these lines are discussed.