P80 CCEGA Echo Protocol for Black Star Binary Mergers: GW241109_115924 as First Candidate

The CCEGA falsification protocol (P49) targeted binary neutron star mergers as primary echo candidates. We extend the protocol to binary black hole mergers whose component masses fall within the CCEGA black star range [4.56, 14.75] M☉. GW241109_115924 — the least massive BBH candidate in GWTC-5.0, with total mass 12.51 M☉ — is identified as the first concrete target. The estimated remnant mass 11.88 M☉ falls within the black star range across all mass uncertainties. Using the t_echo(M) curve from P77, we predict t_echo = 16.4 +8.2/-8.2 ms with radion sidebands Δf ∈ [240, 2400] Hz. O4b strain data are publicly available at GWOSC. This paper constitutes a pre-registered, falsifiable prediction prior to any echo search being conducted.