How many years had it been since he'd last exposed himself to his native solar radiance?

The fact that this is not in line with the - compared to today 30% lower - solar radiance of the early sun has been described as the faint young Sun paradox.

In the play's conclusion, when Frank walks willingly into that darkness, he glows with solar radiance.

"Whew, I'm glad to be in here out of that solar radiance," breathed Otho.

Westward they still gemmed a majestic darkness, for the solar radiance was wan where no heiphts reflected it.

Beryl strode beside him, leonine hair catching glints of solar radiance.

Translucent domes arched over their heads, refracting the solar radiance and generating prism images that shifted slowly with the sun, and more rapidly with the position of the viewer.

The book is often enchanted to glow with a soft solar radiance when it's closed, and some versions are gilded.

(Many variations of this - Malencovich cycles, solar radiance, galactic cosmic rays, etc.)

The atmospheric effect can be removed with Langley extrapolation; this method therefore allows measuring the solar extraterrestrial radiance with ground-based measurements.