Titlebook: Astronomical Photometry; A Guide Chr. Sterken,J. Manfroid Book 1992 Springer Science+Business Media Dordrecht 1992 astronomy.instruments.ob

Conquest

flavonoids

危险

The photomultiplier,The . is the essential part of most professional aperture photometers. It does not record an image, but only measures the amount of incident light. In summary the photomultiplier is a ..

首创精神

Photometric filters,Filters select specific regions from the ultraviolet, visible and infrared region of the electromagnetic spectrum. They are fully described by their thickness and diameter and by their spectral transmission and reflection curves. Categories useful in astronomical photometry are:

Chagrin

Atmospheric extinction,, in its broadest sense, is the reduction of the intensity of radiation as a result of absorption and scattering by the Earth’s atmosphere (see Fig. 6.1). Both processes reduce the radiant flux from a given beam of light (about one sixth of the amount of perpendicularly incident light is extinguished in the visible domain).

Anticonvulsants

Principles of data analysis,The reduction of photometric data consists in calculating the magnitudes and colors of celestial objects on a standard scale. The influences—either random or systematic—of the Earth’s atmosphere and of the instrumentation on the signal have to be removed. The evaluation of the accuracy of the results is the final part of the reduction process.

遗忘

Credence

Introduction,s with measuring the intensity of light”. It is also “the practice of using a photometer”. When measuring monochromatic light quantities, photometric methods are straightforward, but when comparing light sources with different spectral energy distributions, measurements become more problematic.

陈旧

Atmospheric turbulence: scintillation and seeing,y be approximately considered to consist of a constant term, and of a variable quantity. The constant part of attenuation of light is the extinction, whereas the constant term of the deflection of light is the refraction. The rapid variations are random fluctuations—respectively called . and .—which are caused by atmospheric turbulence.

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