A New Eclipsing X-Ray Burster near the Galactic Center: A Quiescent State of the Old Transient A1742-289
With ASCA, we found highly absorbed X-rays from the position of the bright transient source A1742-289 with a variable flux ranging from 8times 10(-12) to 4times 10(-11) erg s(-1) cm(-2) in the 3--10 keV band. We discovered an X-ray burst and eclipses from A1742-289, establishing that A1742-289 is an eclipsing low-mass X-ray binary. Using the black-body radius during an X-ray burst, we estimated the distance of A1742-289 to be about 10 kpc, or near to the galactic center. The burst peak flux was then found below the Eddington limit of a neutron star. Excess soft X-rays during the eclipse were detected, which are interpreted to be scattering by interstellar dust-grains. Since A1742-289 was found to be an X-ray emitter, even in the quiescent state with a moderate but variable flux, and since A1742-289 is lying only 1.3' from the galactic cente r, previously reported X-ray fluxes of the galactic center (Sgr A(*) ) with non-imaging instruments might have suffered due to possible contamination of A1742-289.