1 Introduction

GRB 980519 was detected on 1998 May 19, 12:20:13 UT by CGRO-BATSE and BeppoSAX-GRBM. It was in the field of view of the BeppoSAX-WFC 2, allowing an estimate of its position with a 3 arcmin error circle at R.A. = 23$^{\rm h}$22$^{\rm m}$15$^{\rm s}$ Dec. = $+77^\circ 15$$.\mkern-4mu^\prime$0 (J2000). The GRBM light curve (lasting $\simeq 30$ s) together with the spectral evolution in the 40-700 keV range is shown in Fig. 1. The soft-hard-soft evolution is evident in the plot. In the 2-27 keV WFC band a similar behaviour is observed but the light curve is much more structured than the high energy one and it lasts for $\simeq 180$ s; the emission starts $\simeq 50$ s before the GRB trigger and stops $\simeq 130$ s later (in 't Zand et al. 1998).

  

Figure 1: The 1 s GRBM light curve of GRB 980519 and its power-law photon spectral index evolution

The average spectrum of the GRBM data can be well fitted with a single power-law with a photon spectral index ($N_E\propto E^{-\alpha}$)$\alpha=1.62\,\pm\, 0.10$ with $\chi^2\simeq 1$. The 40-700 keV fluence (over 27 s) is $F_\gamma = (8.1\,\pm\, 0.5)$ 10^-6 erg cm^-2 and the hardness ratio $f_{100-300/50-100} = 2.2 \,\pm\, 0.2$.Description of the method adopted for GRBM spectra deconvolution is reported by Amati et al. (this workshop).

  

Figure 2: 2-10 keV X-ray flux decay as seen by the BeppoSAX MECS. The upper limit to the flux during the burst and the last WFC measured values are shown. Three possible fitted power-law decays are reported