A New Bursting X-Ray Transient: SAX J1750.8–2900

We have analyzed in detail the discovery measurements of the X-ray burster SAX J1750.8-2900 by the Wide Field Cameras on board BeppoSAX in spring 1997, at a position ~1.°2 off the Galactic center. The source was in outburst on March 13 when the first observation started and showed X-ray emission for ~2 weeks. A total of nine bursts were detected, with peak intensities varying from ≈0.4 to 1.0 crab in the 2-10 keV range. Most bursts showed a fast rise time (≈1 s), an exponential decay profile with e-folding time of ≈5 s, spectral softening during decay, and a spectrum which is consistent with few keV blackbody radiation. These features identify them as type I X-ray bursts of thermonuclear origin. The presence of type I bursts and the source position close to the Galactic center favors the classification of this object as a neutron star low-mass X-ray binary. X-ray emission from SAX J1750.8-2900 was not detected in the previous and subsequent Galactic bulge monitoring, and the source was never seen bursting again.