Detection of a Millisecond Periodicity in BATSE Short Gamma-Ray Bursts

Coherent oscillations at kilohertz frequencies have recently been detected in a small number of gamma-ray bursts (GRBs), suggesting quasiperiodic dynamics in their central engines. A prominent example is GRB 230307A, which exhibited a brief, highly coherent, energy-dependent periodic signal interpreted as the possible spin signature of a nascent millisecond magnetar formed after a compact binary merger. Motivated by these developments, we conducted a comprehensive search for similar signals, accounting for both temporal and spectral dependencies, in 532 short GRBs with time-tagged event data recorded by the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory. Within this sample, we identify a single statistically significant case: GRB 960616 (BATSE trigger 5502), in which the ∼30 ms main emission episode is coherently modulated at 1100 Hz, with the strongest modulation above 320 keV and a fractional amplitude of ∼47%. Assuming the presence of a coherent periodic modulation, we use data-driven Monte Carlo simulations to place an upper limit of ∼8% on the fraction of the total radiated energy that can be modulated by the quasiperiodic oscillation. This event, exhibiting a periodicity at ∼0.91 ms, further supports the possibility that millisecond periodicities can arise during GRBs in merger-driven scenarios.