Discovery of SAX J1753.5-2349 and SAX J1806.5-2215: two X-ray bursters   without detectable steady emission
  We report the discovery with BeppoSAX-WFC of two new X-ray sources that were only seen during bursts: SAX J1753.5-2349 and SAX J1806.5-2215. For both sources, no steady emission was detected above an upper limit of 5 mCrab (2 to 8 keV) for 3 10**5 s around the burst events. The single burst detected from SAX J1753.5-2349 shows spectral softening and a black body color temperature of 2.0 keV. Following the analogy with bursts in other sources the burst very likely originates in a thermonuclear flash on a neutron star. The first of two burst detected from SAX J1806.5-2215 does not show spectral softening and cannot be confirmed as a thermonuclear flash. 
J.J.M. in 't Zand (SRON), J. Heise (SRON), J.M. Muller (SRON and   Bepposax-SDC), A. Bazzano (CNR-Ias), M. Cocchi (CNR-Ias),...