Short-lived Jovian decametric events observed with an acousto-optical radio spectrograph

S-bursts and other short-lived events in Jupiter's decametric radio spectra are studied with an acousto-optical radio spectrograph (AORS) and a charge-coupled device (CCD) readout. The lifetimes of regular S-bursts are of the order of tens of milliseconds. Lifetimes of S-bursts that occur in quasi-periodic trains are mostly below 20 ms. Short-lived bursts that do not seem to drift in frequency are also observed. Such bursts (nondrift bursts) may occur in S-trains and at the vertex of tilted-V patterns. The vertex bursts have lifetimes comparable to those of the S-train bursts. Preliminary measurements of the risetimes of bursts indicate that a significant proportion of the vertex bursts exhibit risetimes of less than 2 ms.