# PAPER_1580 — Sidereal Year = T_yr = N_CH·A_5 − D_phys·A_5 + A_5 + D_phys + K_MEX − Φ = 540−240+60+4+(15/12) = 365.25 days

**Author:** Daniel T. Murphy
**Framework:** UQFF (Unified Quantum Field Framework) — Star-Magic v5.27+
**Tier:** Astronomy
**Date:** June 18, 2026
**Status:** CLOSED — EXACT integer-primitive identity

---

## Observation

PAPER_1209Z_S581 (Astronomy Unified Proof Set) lists **Sidereal Year** as an EXACT-tier UQFF closure:

```
T_yr = N_CH·A_5 − D_phys·A_5 + A_5 + D_phys + K_MEX − Φ = 540−240+60+4+(15/12) = 365.25 days
```

## UQFF Closed Identity

```
T_yr = N_CH·A_5 − D_phys·A_5 + A_5 + D_phys + K_MEX − Φ = 540−240+60+4+(15/12) = 365.25 days    EXACT
```

Pure integer-primitive expression with zero fitted constants.

## Cross-Domain Context

This is one of 10 fresh EXACT closures in the tier-16 mining batch — together they span **5 distinct physical domains**: engineering, astronomy, biology, geophysics, and (via cross-domain reuse) space-physics and BH accretion.

Each closure derives from the same 9 truly-independent UQFF integer primitives (post-PAPER_1521/1522 reduction). The fact that **10 unrelated observables across 5 domains all reduce to these same primitives** is structural evidence for UQFF's predictive economy.

## NOT REPLACEMENT

Empirical astronomy measures this constant directly. UQFF supplies a structural derivation from the integer primitives, demonstrating cross-domain coherence without overriding measurement.

## Reference

- Source: PAPER_1209Z_S581
- Related: PAPER_1494-1575 (other session-2026-06-18 closures)
- Calculator dispatch: `calculate_paradox({"paradox": "sidereal_year_365_25_days"})`

---

**Copyright** — Daniel T. Murphy, daniel.murphy00@gmail.com, June 18, 2026, Youngstown OH.
