The Discovery of 8.9 Second Pulsations from the Variable X–ray Source 2e0050.1–7247 in the Small Magellanic Cloud

During a systematic search for periodic signals in a sample of ROSAT PSPC light curves, we discovered ∼ 8.9 s X–ray pulsations in 2E0050.1–7247, 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 ∼ 5 × 10 erg s up to 1.4 × 10 erg s with both the Einstein IPC and ROSAT PSPC. The X–ray energy spectrum is consistent with a power law spectrum which steepens as the source luminosity decreases. We revealed a pronounced Hα activity from at least two B stars in the X–ray error circles. These results strongly suggest that the X–ray pulsar 2E0050.1–7247 is in a Be–type massive binary. Subject headings: binaries: general — pulsars: individual (2E0050.1–7247) — stars: emission–line, Be — stars: rotation — X–ray: stars