P57: 4U 1957+11 as a CCEGA Black Star Candidate — Persistent Luminosity, Absent Quiescence, and Mass Gap Constraints

We identify 4U 1957+11 as the strongest current candidate for a CCEGA black star. The system shows persistent X-ray luminosity over 45+ years without quiescence, absent radio jet, and a compact object mass consistent with the black star regime 4.56–14.75 M☉. We compute the expected QPO frequencies, surface temperature, and echo timescale for the system. The four simultaneous observational criteria from P56 are satisfied. Dynamic mass measurement is the primary pending test.