| Abstract: | Photoelectric measurements have been carried out at Kottamia Observatory site to study night sky brightness and the atmospheric
extinction at different wavelengths. The results show that the mean extinction coefficients are k = 0.41, k = 0.28< and k
= 0.17 mag/air mass during autumn season. These values are almost the same as that obtained by Mikhail (1979) at the same
site during the same season. Results of night sky brightness at different altitudes above the horizon have been obtained.
Complete scan each five degrees step in azimuth have been done at altitudes 50°, 60° and 70° to complete the previous measurements
given by Nawar et al. (1995). Far from the diffuse galactic light, slight variations in night sky brightness with azimuth
have been detected.
This revised version was published online in August 2006 with corrections to the Cover Date. |
