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Sky Luminance Analysis at Deep Sky Chile by DarkSkyLab
Before analyzing the results of the measurements carried out on the Deep Sky Chile site in the Rio Hurtado valley, it is important to understand that this is an exceptional site in several respects:
- First of all, there are hardly any clouds! This is of course quite unusual for people who like us study light pollution mainly in the territory of Metropolitan France. From this point of view, this site constitutes a very special case where everything is simplified from the point of view of the study of the luminosity of the sky. Indeed, the presence of clouds makes the luminosity of the sky background extremely erratic with significant variations over durations of less than a minute.
- Then, the region where the site is located is very little polluted by the presence of light sources nearby. Here too, this leads to a very strong simplification in the study of the luminosity of the sky since the variations observed are almost exclusively due to natural causes (Moon, Milky Way, star fields, zodiacal light, “airglow”, …).
- Finally, the sky quality is exceptional on this site with an average seeing value of less than an arc second (i.e. atmospheric turbulence is very low). This helps to produce very stable measurements of sky background brightness.
We can therefore say that the Deep Sky Chile site constitutes a laboratory for studying the natural causes of the luminosity of the sky!