Discovery of optical bursts from an X-ray burst source, MXB1735-44.

GRINDLAY, J. E.; MCCLINTOCK, J. E.; CANIZARES, C. R.; PARADIJS, J. VAN; COMINSKY, L.; LI, F. K.; LEWIN, W. H. G.

THE detection of optical bursts1 from the X-ray burst source MXB1735-44 (ref. 2) is reported here. Since the discovery of X-ray burst sources3, considerable efforts have been made to understand their nature. Recent reviews4-7 summarise the X-ray observations and proposed models which include accretion instabilities on to neutron stars or black holes and thermonuclear flashes on a neutron star (see also refs 8,9). As yet no final consensus of opinion exists about the burst mechanism or source geometry. Detection of bursts in other parts of the spectrum (radio, IR, or optical) could place significant limits on conditions at the source and provide additional tests of models. Thus an extensive campaign to monitor bursters was organised10 in 1977, and significant upper limits for emission (at burst times) in the radio11,12 and optical13-15 have already been reported. Our burst observations of the optical counterpart of 4U1735-44 (refs 16, 17), an intense persistent X-ray source associated with the burster MXB1735-44 (refs 2, 7), were made with considerably higher sensitivity than previously.

Nature, 1978, Vol 274, Issue 5671, p567

0028-0836

Academic Journal

10.1038/274567a0