Photogravitational Model: Mass and Gravitational Constant Derivation with System-Specific Φ Parameter

This paper presents a validated analytical framework for determining both the masses of stars and compact objects, and the gravitational constant (G), using only directly observable parameters: bolometric luminosity (L), characteristic radius (R), and the photogravitational index (Φ). It is shown that Φ is not a universal constant, but rather a system-specific parameter that must be recalculated for each object studied. Applications to the Sun and to the Cygnus X-1 black hole system confirm the model’s accuracy when Φ is derived directly from empirical system data.