Swift-XRT detection of x-ray pulsations from IGR J18173-2509 and SWIFT J2138.8+5544

As part of a systematic search for periodicities in the Swift-XRT public light curves (energy range 0.5-10 keV) performed with the ad hoc developed software Swift Automatic Timing ANAlysis of Serendipitous Sources at Brera And Roma Astronomical Observatories (SATANASS @ BAR), we discovered two new X-ray pulsators. A periodic signal at about 830.70 +/- 0.02 s (uncertainties are at 1 sigma c.l.; power spectrum detection significance of > 5 sigma) was detected in the X-ray flux of IGR J18173-2509, an INTEGRAL source recently classified as a Cataclysmic Variable (CV) through optical spectroscopy.