The central spot in the diffraction pattern of the image of a star at the focus of a telescope, named after George Airy. It is surrounded by several fine diffraction rings like the rings around the bull抯-eye of a target. The size of the Airy disk, given approximately in radians by 1.22 times the wavelength of light times the focal ratio, is the same for all telescopes of a given size and is less in instruments of larger aperture. (It is one of the quirks of astronomy that bigger telescopes produce smaller images of stars.) In practice, however, atmospheric turbulence, unless compensated for, results in a false disk that is larger than the Airy disk. 5TzMv3;in2  
'nW:2(J  
The ratio of the focal length (F) of a mirror or lens to its diameter (D) expressed as a number, f/# = F/D. Borrowing the language of photography, small focal ratios, below about f/6, are said to be fast and result in a brighter image for a given aperture. Large focal ratios, equal to or above about f/8, are said to be slow. V

I37  
mxDy!:@=  
Xj|j\2$ 0  
從上面的英文可以知道 AIRY DISK的直徑=1.22*波長(zhǎng)*F# !U=;e 科技| 太仆寺旗| 丹巴县| 溧水县| 昌都县| 建湖县| 九龙城区| 明光市| 保康县| 玉林市| 晋江市| 兴义市| 太仆寺旗| 永昌县| 卓尼县| 樟树市| 常山县| 都匀市| 长白| 咸阳市| 什邡市| 安义县| 绍兴市| 射阳县| 乌拉特前旗| 澄江县| 安达市| 大悟县| 牙克石市| 莱州市| 探索| 黄梅县| 长丰县| 津南区| 普定县| 延边| 庆元县| 安阳县| 永靖县| 凌云县| 怀宁县|