Calculation — Xularreis

STEP 01 CIVIL TIME → JULIAN DATE CONTINUOUS DAY COUNT · J4713BC

UTC TIME—

UNIX TIMESTAMP (ms)—Date.getTime()

JULIAN DATE—unix/86400000 + 2440587.5

T (Julian centuries from J2000.0)—(JD − 2451545.0) / 36525

STEP 02 GREENWICH MEAN SIDEREAL TIME IAU 1982 POLYNOMIAL

GMST (raw degrees)—280.46061837 + 360.98564736629·(JD−J2000) + …

GMST (normalized 0–360°)—

GMST (hours)—

STEP 03 NUTATION CORRECTION 4-TERM TRIGONOMETRIC · IAU 1980

Ω (lunar ascending node)—125.04452 − 1934.136261·T

L₀ (mean solar longitude)—

L₁ (mean lunar longitude)—

ε₀ (mean obliquity)—23.439291111 − 0.013004167·T

ΔΨ (nutation in longitude)—arcsec

Δε (nutation in obliquity)—arcsec

ε (true obliquity)—

Equation of equinoxes—ΔΨ · cos(ε)

STEP 04 APPARENT SIDEREAL TIME GAST → LAST

GAST (Greenwich apparent)—

OBSERVER LONGITUDE—

LAST (local apparent)—GAST + longitude

LAST (hours)—

STEP 05 NINE WITNESSES — LOCAL COORDINATES SPHERICAL TRIGONOMETRY · BENNETT REFRACTION

STAR	RA (h)	DEC (°)	HA (h)	ALT (°)	AZ (°)	REF (′)	STATUS

STEP 06 PHI HARMONIC — 36 PAIRS PENTAGON NORMALIZATION · 108°

DOMINANT HARMONIC

—

STEP 07 TRANSIT CLASSIFICATION HOUR ANGLE WINDOWS · HONEST NULLS

RISING (HA 18–24h, alt > −2°)—

ZENITH (highest visible)—

SETTING (HA 0–6h, alt > −2°)—

OBSERVER LATITUDE—

VISIBLE STARS (alt > 0°)—