Missing Third Flares Force Rethink of rpTDE Duty Cycles and Supermassive Black Hole Feeding

The arXiv preprint (abs/2606.06578) uses non-detections of expected third flares in TDE 2022dbl and TDE 2020vdq to place upper limits of L_UV/optical ≲ 10^42 erg s^-1, roughly 30 times fainter than prior events. Semi-analytical modeling of stellar orbits and tidal encounters favors a main-sequence star on a promptly bound orbit with a deep initial pericenter passage, producing at most two luminous flares before the remnant is either ejected or circularized into a faint accretion flow. This is a preprint; no peer review has occurred. Methodology rests on two events, Poisson probability calculations against average TDE rates (~10^-5 gal^-1 yr^-1), and assumed periodicity—limitations that leave room for extreme rate dispersion or selection biases. What coverage missed is the direct tightening of flare duty-cycle models: if most rTDEs yield only two observable peaks within a few-year window, accretion-disk feeding episodes are shorter than previously modeled, lowering predicted optical depths and altering expectations for LSST and ZTF yields. Cross-referencing with van Velzen et al. (2021) on volumetric TDE rates and the 2023 analysis of ASASSN-22ci light curves shows the observed flare spacing is inconsistent with binary-star double disruptions, reinforcing the rpTDE channel. These constraints imply that nuclear stellar dynamics around 10^6–10^7 M_⊙ black holes favor prompt capture over gradual inspiral, reshaping estimates of how frequently SMBHs are fed by partial disruptions.