Calculadora de Posição do Sol (Declinação)

The Sun Position Calculator (Declination) determines the solar declination, an angle measuring the Sun's position relative to the celestial equator. Declination varies throughout the year, affecting day length, solar altitude, and solar radiation intensity. The calculator uses the formula δ = 23.45° × sin(2π × (284 + N) / 365), where N is the day of the year (1 to 365). The result is in degrees, ranging from -23.45° (winter solstice in the Northern Hemisphere) to +23.45° (summer solstice).

This tool is useful for solar energy professionals, architects, farmers, and astronomy enthusiasts. For instance, when sizing solar panels, declination helps calculate the optimal tilt angle to maximize energy capture. In agriculture, declination influences planting and harvest planning, especially at high latitudes. It is also used in daylighting design and climate studies.

When using the calculator, enter the day of the year (N) from 1 to 365. For leap years, consider day 366, but the formula is an approximation and may have slight variations. Note that the calculated declination is for true solar noon. For precise solar position (azimuth and altitude), other variables like latitude and longitude are needed. The calculator assumes a simplified circular orbit, ignoring Earth's eccentricity.