Dark-sky movement — The dark sky movement is a campaign by people who want to reduce light pollution so people can see the stars, to reduce the effects of unnatural lighting on the environment, and to cut down on energy usage. The movement started with professional… … Wikipedia
International Dark-Sky Association — The IDA s logo The International Dark Sky Association (IDA) is a U.S. based non profit organization incorporated in 1988 by founders Dr. David Crawford, a professional astronomer, and Dr. Timothy Hunter, a medical doctor/amateur astronomer. The… … Wikipedia
Dark-sky preserve — A dark sky preserve is an area, usually surrounding a park or observatory, that is kept free of artificial light. The purpose of a dark sky preserve is generally to promote astronomy. Because different national organizations have worked… … Wikipedia
Échelle de Bortle — L’échelle de Bortle d évaluation de la qualité du ciel noir (Dark Sky Scale pour les anglophones) est une échelle de mesure de la pollution lumineuse créée pour l édition de février 2001 du magazine Sky Telescope par John Bortle [1]. Exemple de… … Wikipédia en Français
Echelle de Bortle — Échelle de Bortle L échelle de Bortle est une échelle de mesure de la pollution lumineuse créée pour l édition de février 2001 du magazine Sky Telescope par John Bortle. C est une description de la noirceur du ciel basée sur l observation de… … Wikipédia en Français
Échelle de bortle — L échelle de Bortle est une échelle de mesure de la pollution lumineuse créée pour l édition de février 2001 du magazine Sky Telescope par John Bortle. C est une description de la noirceur du ciel basée sur l observation de différents objets… … Wikipédia en Français
Darkness — Dark redirects here. For other uses, see Dark (disambiguation). This article is about the absence of light. For other uses, see Darkness (disambiguation). Light shining on a part of a bush. Where light is not reflected, there is darkness.… … Wikipedia
Light pollution — This article is about light pollution in the visible spectrum. For information on pollution in the radio spectrum, see radio spectrum pollution. This time exposure photo of New York City at night shows skyglow, one form of light pollution … Wikipedia
Apparent magnitude — Asteroid 65 Cybele and 2 stars with their magnitudes labeled The apparent magnitude (m) of a celestial body is a measure of its brightness as seen by an observer on Earth, normalized to the value it would have in the absence of the atmosphere.… … Wikipedia
Skyglow — (or sky glow), is a kind of light pollution, visible by the glowing effect seen in the skies over many cities and towns as a dome of light. Light domes can also appear above over illuminated rural shopping centers, stadia, and the like. Skyglow… … Wikipedia
