Kirimure.

Solarium Solar Trajectory & Ephemeris Studio
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Astronomical Model Active
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Subsolar Point: --
Daylight
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Daily Path
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UTC Time 12:00:00
Local Time 09:00
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Subsolar Point Telemetry
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Photoperiod --h --m
Solar Phase Daylight
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Solar Astronomy & Ephemeris Guide
What is the Subsolar Point and Solar Declination?
The subsolar point is the exact spot on Earth where the Sun is directly overhead at the zenith (90° above horizon). Its latitude corresponds exactly to the solar declination (δ), which oscillates between +23.44° (Tropic of Cancer) on the June solstice and -23.44° (Tropic of Capricorn) on the December solstice due to Earth’s axial tilt of 23.44°.
What is the Equation of Time (EoT)?
Because Earth’s orbit is elliptical (eccentricity e ≈ 0.0167) and tilted with respect to the celestial equator, apparent solar time runs faster or slower than uniform clock time. The Equation of Time is the difference between apparent solar time and mean solar time, varying between -14.2 minutes in mid-February to +16.4 minutes in early November.
Why does the Day/Night Terminator curve shift across seasons?
The terminator is a great circle on the globe 90° away from the subsolar point. When projected onto a flat rectangular (equirectangular) world map, this great circle projects as a sinusoid: φ = arctan(-cos(λ - λ_sub) / tan(δ)). During equinoxes (δ = 0°), the curve straightens into vertical meridians. During solstices, it reaches the polar circles at ±66.56°, causing the Arctic or Antarctic midnight sun.
What is an Analemma?
If you record the Sun’s position in the sky at the exact same hour every day of the year, it traces a figure-8 curve called the Analemma. On the world map, our "Annual Analemma" toggle plots the yearly ground track of the subsolar point at the currently chosen time of day, displaying the interplay of Earth’s axial tilt and orbital eccentricity.
How are local sunrise, sunset, and solar noon computed?
Solar noon occurs when the Sun crosses the observer’s local meridian: T_noon = 12h - (Longitude / 15°) - (EoT / 60). Sunrise and sunset are then calculated by solving the spherical triangle where solar altitude equals -0.833° (accounting for 16 arcminutes of solar disc radius plus 34 arcminutes of atmospheric refraction).