منابع مشابه
Chromaticity in all-reflective telescopes for astrometry
Aims. Chromatic effects are usually associated with refractive optics, so reflective telescopes are assumed to be free from them. We show that all-reflective optics still bears significant levels of such perturbations, which is especially critical to modern micro-arcsecond astrometric experiments. Methods. We analyze the image formation and measurement process to derive a precise definition of ...
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Several lamellar gratings of 18-in. aperture, with 300 diffraction elements per inch, have been made for determining stellar spectra with wide angle telescopes. Central orders are missing at lambda4800, and weak at adjacent wavelengths. The two, equal first orders are about l(m) weaker than spectra by a prism or echelette grating. Dispersion is linear. The procedure of manufacture is adaptable ...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1984
ISSN: 0252-9211
DOI: 10.1017/s025292110010661x