A search for optical bursts from the rotating radio transient J1819−1458 with ULTRACAM – II. Simultaneous ULTRACAM–Lovell Telescope observations

The rotating radio transient (RRAT) J1819−1458 exhibits ∼3 ms bursts in the radio every ∼3 min, implying that it is visible for only ∼1 s per day. Assuming that the optical light behaves in a similar manner, long exposures of the field would be relatively insensitive due to the accumulation of sky photons. A much better way of detecting optical emission from J1819−1458 would then be to observe with a high-speed optical camera simultaneously with radio observations, and co-add only those optical frames coincident with the dispersion-corrected radio bursts. We present the results of such a search, using simultaneous ULTRACAM and Lovell Telescope observations. We find no evidence for optical bursts in J1819−1458 at magnitudes brighter than i′= 19.3 (5σ limit). This is nearly 3 mag fainter than the previous burst limit, which had no simultaneous radio observations.