Photogravitational Derivation of G and Stellar Ordering on the Φ Spectrum

This note introduces the photogravitational index (Φ) as a dimensionless parameter for classifying stellar structure by the balance of radiation and gravity. Defined  

  Φ = L / (M × a)  

it enables comparison across stellar types. Using TIC catalog data, we computed Φ for 20 stars (see Table 1). A clear correlation between Φ and luminosity is shown in Figure 1. High Φ values reflect radiative dominance, while low Φ values indicate gravitational compression. This supports Φ as a continuous, physical classifier for stellar structural states.

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