Autor: Tau'olonga
Fecha: julio 2006
Licencia: Creative Commons. Puede copiarse, debe mencionarse al autor
Descripción: Arco diurno del Sol, cada hora en los 2 solsticios, vistos en el cielo desde una latitud de 20 grados. También se muestran "soles crepusculares" hasta los -18º de elevación.

"The day arcs at 20° latitude. The Sun culminates at 46.56° altitude in winter and 93.44° altitude in summer. In this case an angle larger than 90° means that the culmination takes place at an altitude of 86.56° in the opposite cardinal direction. For example in the southern hemisphere, the Sun remains in the north during winter, but can reach over the zenith to the south in midsummer. Summer days are longer than winter days, but the difference is no more than two or three hours. The daily path of the Sun is steep at the horizon the whole year round, resulting in a twilight of only about one hour."