We report on the discovery of X-ray pulsations from the Be/X-ray system LS 992/RX J0812.4–3114 during an RXTE observation .
From a timing analysis of the source we obtained a barycentric pulse period of 31.8851 \pm 0.0004 s. The pulse profile is highly structured and departs from a pure sinusoidal shape .
It shows a sharp dip that may indicate absorption by the accretion flow .
The energy spectrum from 3-30 keV can be fitted by a power-law model with an exponential cut-off in accordance with other X-ray pulsars .
The X-ray luminosity is estimated to be \sim 1.1 \times 10 ^ { 36 } erg s ^ { -1 } in the energy range 3-30 keV , assuming a distance of \sim 9 kpc .