2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106501We apply the recently developed Log N - Log S test of compact star cooling theories for the first time to hybrid stars with a color superconducting quark matter core. While there is not yet a microscopically founded superconducting quark matter phase which would fulfill constraints from cooling phenomenology, we explore the hypothetical 2SC+X phase and show that the magnitude and density-dependence of the X-gap can be chosen to satisfy a set of tests: temperature - age (T - t), the brightness constraint, Log N - Log S, and the mass spectrum constraint. The latter test appears as a new conjecture from the present investigation.10 pages, 9 figures, 1 tableNuclear TheoryAstrophysicsHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext