The discovery of 96 s pulsations from the variable X-ray source 1SAX J0544.1-710 in the Large Magellanic Cloud

We report the discovery of a similar to 96 s period X-ray pulsar in the direction of the Large Magellanic Cloud (LMC). The BeppoSAX X-ray spectrum is well fitted by an absorbed power-law model with photon index similar to 0.5. The unabsorbed luminosity in the 2-10 keV energy range is similar to 9 x 10(35) erg s(-1). The BeppoSAX position (40 " uncertainty radius) of 1SAX J0544.1-710 was found to be consistent with that of the ASCA source AX J0448-70.4 and WGACAT (ROSAT PSPC) source 1WGA J0544.1-710. The source was detected four times between 1991 and 1996 at luminosity levels from similar to 3 x 10(35) to 9 x 10(35) erg s(-1) (2-10 keV), while during a relatively deep ROSAT HRI observation an extrapolated 2-10 keV luminosity upper limit of similar to 1 x 10(35) erg s(-1) was obtained. Timing analysis of the ASCA data confirmed the BeppoSAX period discovery. Longterm flux variability is evident in the ROSAT and Einstein data. We revealed a pronounced H alpha activity from a bright (V similar or equal to 15) likely Be-type star within the 8 " ROSAT PSPC error circle. Its optical spectrum shows it is located in the LMC. These results strongly suggest that 1SAXJ0544.1-710 is a transient X-ray pulsar in a massive binary system.