The discovery of 8.9 second pulsations from the variable X-ray source 2E 0050.1-7247 in the Small Magellanic Cloud

During a systematic search for periodic signals in a sample of ROSAT PSPC light curves, we discovered similar to 8.9 s X-ray pulsations in 2E 0050.1-7247, a variable X-ray source in the Small Magellanic Cloud. The source was detected several times between 1979 and 1993 at luminosity levels ranging from similar to 5 x 10(34) ergs s(-1) up to 1.4 x 10(36) ergs s(-1) with both the Einstein IPC and ROSAT PSPC. The X-ray energy spectrum is consistent with a power-law spectrum that steepens as the source luminosity decreases. We revealed a pronounced H alpha activity from at least two B stars in the X-ray error circles. These results strongly suggest that the X-ray pulsar 2E 0050.1-7247 is in a Be-type massive binary.