A search for optical bursts from the rotating radio transient J1819–1458 with ULTRACAM

We report on the search for optical bursts from J1819–1458, a member of the recently discovered Rotating Radio Transients (RRATs). J1819–1458 exhibits 3 millisecond bursts with a peak flux of f ν = 3.6 Jy every ∼ 3.4 minutes, implying that it is visible for only ∼ 1 second per day at radio wavelengths. Assuming that the optical light behaves in a similar manner, the most sensitive way of detecting RRATs is hence not to take long exposures of the field, but instead to capture individual bursts using a high-speed camera mounted on a large aperture telescope. Using ULTRACAM on the 4.2-m William Herschel Telescope (WHT) we obtained 97 100 images of the field of J1819–1458, each of 18.1 milliseconds exposure time and with essentially no dead-time between the frames. We find no evidence for bursts in u, g and i at magnitudes brighter than 15.1, 17.4 and 16.6 (5σ), corresponding to fluxes of less than 3.3, 0.4 and 0.8 mJy at 3560Å, 4820Å and 7610Å, respectively.