2011MNRAS.414L.104D

We report on the Swift detection of a thermonuclear X-ray burst from the very-faint quasi-persistent neutron star X-ray binary XMMU J174716.1–281048, which triggered the satellite's Burst Alert Telescope (BAT) on 2010 August 13. Analysis of the BAT spectrum yields an observed bolometric peak flux of ≃ 4.5 {x} 10^–8 erg/cm2/s, from which we infer a source distance of ≲ 8.4 kpc. Follow-up observations with Swift's X-ray Telescope (XRT) suggest that the event had a duration of ≃ 3 h and a total radiated energy of ≃ 9 {x} 10⁴⁰ erg, which classify it as an intermediately long X-ray burst. This is only the second X-ray burst ever reported from this source. Inspection of Swift/XRT observations performed between 2007 and 2010 suggests that the 2–10 keV accretion luminosity of the system is ≃ 5 {x} 10³⁴ erg/s for an assumed distance of 8.4 kpc. Despite being transient, XMMU J174716.1–281048 appears to have been continuously active since its discovery in 2003.