among the shortest known for HMXBs especially for those containing a Be star primary. If SMC X-2 follows the loose relation between $P_{pulse}$ and $P_{orbit}$ seen in Be/X-ray binaries [@Corbet86] then its orbital period may be around 15 days. The pulse profiles appear to be correlated with $L_{X}$, similar changes were observed in XTE J0052-723 and also the 51 s XTE pulsar that was initially reported as having a period of 25.5s by @lamb2001. The temporal coverage of the [[*RXTE* ]{}]{}observations of SMC X-2 presented here were sufficient to track the luminosity and pulse period behavior reasonably closely for the duration of an entire outburst. A gap in coverage occurred between MJD 51600-51640 and certain observed properties suggest that 2 outbursts may have occurred. Evidence for this interpretation comes from the flux history and the pulse period variations. If two separate outbursts did in fact occur, then an estimate can be made that the orbital period is less than approximately 70 days, by taking the difference of the dates on which the two periods of spin-up began.

XTE J0052-723 (4.78s)
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Pulsations with a 4.78 s period were detected on 2000 December 27 during an observation of pointing position 5. 