Abstract

Zenith sky brightness at totality was observed to be about four orders of magnitude lower than that for a normal day sky. The spectral distributions in terms of an effective blackbody temperature for the range 4100–8000 Å were 5000 K, 9000 K, and 11,000 K for the twilight, control day sky, and totality, respectively, indicating a shift toward the shorter wavelength at totality. The polarization measured in the sun’s vertical plane 90° away from the sun was 4% and 0.6% at 4750 Å and 6000 Å, respectively. Both colors showed a change in the plane of polarization of about 50° at the time of totality. From the change in the plane of polarization it is estimated from the primary component reduced by about an order of magnitude at totality of the eclipse.

© 1971 Optical Society of America

Measurements of the Zenith Sky Brightness and Color During the Total Solar Eclipse of 12 November 1966 at Quehua, Bolivia

B. S. Dandekar
Appl. Opt. 7(4) 705-710 (1968)

Zenith Sky Brightness and Color Change During the Total Solar Eclipse of 12 November 1966 at Santa Ines, Peru

D. A. Velasquez
Appl. Opt. 10(6) 1211-1214 (1971)

Spatiotemporal change of sky polarization during the total solar eclipse on 29 March 2006 in Turkey: polarization patterns of the eclipsed sky observed by full-sky imaging polarimetry

Brigitta Sipoćz, Ramón Hegedüs, György Kriska, and Gábor Horváth
Appl. Opt. 47(34) H1-H10 (2008)

Sky Brightness and Polarization During the 1973 African Eclipse

Glenn E. Shaw
Appl. Opt. 14(2) 388-394 (1975)

Summary of Sky Brightness Measurements During Eclipses of the Sun

W. E. Sharp, S. M. Silverman, and J. W. F. Lloyd
Appl. Opt. 10(6) 1207-1210 (1971)