Abstract:
We report the detection of several quasiperiodicities around 0.6–2.5 days in the optical emission of the blazar S4
0954+658. The source was observed by the Transiting Exoplanet Survey Satellite in six sectors and it showed
these features in all but one of them, with a quasiperiodic oscillation of 1.52 days apparently present in portions of
four of them. We used the generalized Lomb–Scargle periodogram method to search for significant signals and we
confirmed them using a weighted wavelet transform for time–frequency domain analyses. We discuss several
possible explanations for these rapid quasiperiodic variations and suggest that an origin in the innermost part of the
accretion disk is most likely. Within this framework, we provide estimates for the mass of the black hole at the core
of this blazar.
