Parhelic-circle sentence example
parhelic-circle
- Passing through the luminary and parallel to the horizon, there is a white luminous circle, the parhelic circle (P), on which a number of images of the luminary appear.
- The other images on the parhelic circle are the paranthelia (q) and the anthelion (a) (from the Greek av-ri, opposite, and iXcos, the sun).
- Thomas Young explained the parhelic circle (P) as due to reflection from the vertical faces of the long prisms and the bases of the short ones.
- When the sun is near the horizon the rays fall upon the principal section of the prisms; the minimum deviation for such rays is 22 °, and consequently the parhelia are not only on the inner halo, but also on the parhelic circle.
- Double internal reflection by a triangular prism would form a single coloured image on the parhelic circle at about 98° from the sun.Advertisement
- The emerging rays are parallel to their original direction and form a colourless image on the parhelic circle opposite the sun.
- To the right of the 120° parhelion, the otherwise colorless parhelic circle is very slightly blue ~ the ' blue spot ' .
- When the sun is near the horizon the rays fall upon the principal section of the prisms; the minimum deviation for such rays is 22 °, and consequently the parhelia are not only on the inner halo, but also on the parhelic circle.
- Double internal reflection by a triangular prism would form a single coloured image on the parhelic circle at about 98° from the sun.