CHILEAN NAVY HYDROGRAPHIC AND OCEANOGRAPHIC SERVICE
Light and Darkness
The Hydrographic and Oceanographic Service of the Chilean Navy (SHOA) informs that the time on all the information published “on its website, mobile applications, and nautical publications” is conveyed in the time zone
UTC – 4 for Continental Chile and Antarctic Territory, and UTC – 6 for Western Insular Chile.
SOLSTICIOS Y EQUINOCCIOS 2020
The time at which the Sun’s center is located between 18 degrees and 50 minutes of depression, and occurs twice a day: before sunrise and just after sunset. It is the moment when the sky is illuminated because the light of the Sun illuminates the upper layers of the atmosphere.
Civil Twilight begins or ends when the Sun’s center is 6 degrees below the horizon. At this time, first magnitude starts and planets begin to disappear (in the morning) or to become visible (in the evening). Objects are easily distinguished and the sea horizon is clearly visible. When the Sun is below this position, city activities require artificial illumination.
The Nautical twilight begins or ends when the Sun’s center is 12 degrees below the horizon line. At this moment, the sea horizon begins to be perceived (in the morning) or to disappear (in the evening), and first and second magnitude starts used by sailors to determine the position of their vessel become visible at a glance.
The Astronomical twilight begins or ends when the Sun’s center is 18 degrees below the horizon line. At this moment, it is night or absolute darkness, and stars up to the sixth magnitude are visible at a glance.