LIGHTING REQUIREMENTS NEAR ASTRONOMICAL OBSERVATORIES (PO97, 1151-1156)

Nearly all astronomy at visible wavelengths involves the study of very faint objects in the night sky. Astronomy is therefore extremely vulnerable to the impact of artificial light, which can produce skyglow, making the night sky brighter. Artificial light can travel enormous distances in Earth?s atmosphere, limited only by the curvature of the Earth. Astronomical observatories must therefore be carefully protected by lighting regulations that extend for distances up to 300 km from the observatory. Astronomy is particularly vulnerable to blue light, which is becoming more common due to widespread use of LEDs. The methods being used to protect the major astronomical observatories in Hawaii will be described.