Search for short bursts in gamma-ray emission from COS-B pulsars.

Selected COS-B arrival times of the gamma-ray photons coming from the directions of the three known gamma-ray pulsars (Crab, Vela and Geminga) were searched for short (<1 hour) transient emission. No bursts were detected; the upper limit for detection going from a factor of 20 up to a few thousand times the steady pulsar flux for decreasing burst duration. An extension of the maximum likelihood method used here in order to investigate within the whole field-of-view of the experiment is described, with the aim to apply it to the existing COS-B data and subsequently to the GRO-EGRET data where the ten times higher statistics than COS-B could reveal the presence of bursts in positions of the sky where no significant steady sources are seen.