Light pollution and its spectral behavior close the astronomical observatories
Authors:
M. Kocifaj
Image & caption:
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Image caption::
Numerically simulated spectral radiance of nightsky at wavelength 551 nm. Distances of the measuring point to centre of the circular town with radius 2 km are: 1 km (top-left), 2 km (top right), 4 km (bottom-left) and 10 km (bottom right panel).
Description:
Any ground-based astronomical observation is affected by diffuse (obtrusive) skylight. The light pollution varies substantially with the direction of observation, atmospheric conditions, the characteristics of ambient environment and also a wavelength at which the measurement is made. Spectral characteristics of stray light are particularly important in astrophotometry and in processing the measurements obtained by means of narrowband filters. As a part of international cooperation, we succeeded to demonstrate how the intensity of stray light depend on the spatial distribution and type of artificial light sources. Specifically, we analyzed the impact of high pressure sodium lamps on the spectral radiances (assuming a concentration of atmospheric pollutants is highly variable). Knowledge of this type is extremely important in correction and interpretation of traditional photometric data. The diffuse light was numerically simulated for two Slovak observatories. It was shown that the spatial distribution of lamps may affect the spectra of astronomical objects if the observations are made in the vicinity of a larger city (e.g. Vartovka in Banská Bystrica).
Reference:
Monthly Notices of the Royal Astronomical Society 403, 2105-2110 (2010); Monthly Notices of the Royal Astronomical Society 409, 1203-1212 (2010)
SK
SAS
