SIMBAD references

We use time-resolved spectroscopy of thermonuclear X-ray bursts observed from SAX J1748.9-2021 to infer the mass and the radius of the neutron star in the binary. Four X-ray bursts observed from the source with the Rossi X-ray Timing Explorer enable us to measure the angular size and the Eddington limit on the neutron star surface. Combined with a distance measurement to the globular cluster NGC 6440, in which SAX J1748.9-2021 resides, we obtain two solutions for the neutron star radius and mass, R = 8.18±1.62 km and M = 1.78±0.3 M_☉ or R = 10.93±2.09 km and M = 1.33±0.33 M _☉.