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A direct and more general calculation of the limb effect connected with red-shift observations is obtained. Result agrees
completely, in its general form, with that obtained from observations of the solar spectra but with different value for the
maximum effect.
This revised version was published online in July 2006 with corrections to the Cover Date.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Evaporation from Lake Qarun and its water budget 总被引：1，自引：0，他引：1
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In the nearest neighbour method of the random distribution of N objectson a sphere surface the variable (N-1) sin2(α/2) isproposed to be used instead of the angular distance α. Thenboth the expected mean and variance equal to one for large N, and both theStudent's test and F-test are especially simple. An illustrative applicationshows that the superclusters – collected in the All-Sky Catalogues ofSuperclusters of Abell-ACO Clusters – need not be distributedrandomly. 相似文献
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Photoelectric observations of night sky brightness at different zenith distances in blue, yellow and red colours have been
carried out at Abu-Simbel site. Variations in the night sky brightness and (B-V) colour index with time are detected. These
variations have been explained by the change of the galactic latitude of the observed point with time. The deduced results
of night sky brightness have been compared with that obtained before at other sites. It has been found for both blue and yellow
colours, that Abu-Simbel is the darkest site especially for zenith distances equal or greater than 60°. The present values
of night sky brightness and colour have been obtained for the first time at Abu-Simbel site. The average night sky brightness
at the galactic plane is 22.58 mag/arc sec2 for blue and 21.66 mag/arc sec2 for yellow.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Photoelectric measurements of the night sky brightness and the light pollution of Kottamia Observatory have been carried out and the deduced results are expressed in mag/sec2. The maximum brightness of the sky in the direction of Cairo city at zenith distance 45° and azimuth 70° when the sun is almost 60° below the horizon are 22.68; 21.54 and 19.82 mag/sec2 for blue, yellow and red colours respectively. The corresponding values of night sky background are 22.94; 21.85 and 20.14 mag/sec2 respectively.The isophotes of the sky brightness at Kottamia Observatory have been drawn for blue, yellow and red colours. The variations of the night sky brightness and the (B-V) colour index with altitude of the observed point have been studied.The light pollution and the night sky brightness at the site of Kottamia Observatory is compared with that deduced by different investigators at other sites. It has been shown that the sky brightness at zenith distance 45° at Kottamia Observatory site is similar to Kitt Peak and Palomar Observatory sites. Kottamia Observatory site is slightly brighter than Junipero Serra while it is darker than Mount Hamilton and San Jose sites. The comparative results have been carried out at blue and yellow colours. No comparison is obtained at red as there is no data published for the red colour. 相似文献
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