Optical Sky Brightness at Cerro Tololo Inter-American Observatory from 1992 to 2006

ABSTRACT We present optical ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $UBVRI$ \end{document} ) sky brightness measurements from 1992 through 2006. The data are based on CCD imagery obtained with the CTIO 0.9, 1.3, and 1.5 m telescopes. The B‐ and V‐band data are in reasonable agreement with measurements previously made at Mauna Kea, although on the basis of a small number of images per year, there are discrepancies for the years 1992 through 1994. Our CCD‐based data are not significantly different than values obtained at ...