During a total eclipse the sun is completely hidden, making it pitch dark just as if the sun had set. But during an annular eclipse, where the moon covers the sun, things don’t get totally dark because the sun peeks around around the edges of the moon. Even 1% of the sun is enough to make it bright out! The sun is roughly 460,000 times as bright as the full moon, so if an annular eclipse is just 1/10 as bright as the regular sun, then it’s still 46,000 times as bright as the moon.
-Tomoko Ono, “A Lesson Just In Time For The Eclipse”
太陽が完全に隠れる皆既日食の場合、日が落ちたように真っ暗になるのですが
金環日食では太陽は月の周囲からはみ出していますから、あたりは真っ暗に
なりません。太陽って１％でも見えていれば明るいんです。
太陽の明るさは満月の明るさの約４６万倍です。
金環日食の明るさがその１割だとすると、満月の約４万６０００倍です。
ーー小野智子さんが『金環日食すべりこみ講座』の中で