2S 1254-690

T. J.-L. Courvoisier and A. Peacock, European Space Agency: and M. Pakull, Technische Hochschule, Berlin, report the discovery of the first type 1 x-ray burst clearly associated with 2S 1254- 690. The optical counterpart had been shown to be very similar to counterparts of other x-ray bursters (Mason et al. 1980, Nature 287, 512), but no x-ray burst associated with this source had previously been observed. EXOSAT observed the source for 6 hr on Feb. 5. The burst occurred at 7h35m UT and was characterized by two components: the first decayed in ~ 4.5 s and the second in ~ 20 s. The temperature associated with the first component was 1.7 keV, and that associated with the slow decay was 1.1 keV. A set of deep dips in the EXOSAT lightcurve occurred 10 min after the burst. The lowest intensities registered then were near zero.