Sentence Examples

  • In the neighbourhood surrounding the penumbra the granules appear to be packed more closely, forming brilliant patches called faculae.
  • Each spot shows with more or less completeness a ring-shaped penumbra enclosing a darker umbra; the umbra, which looks black beside' the photosphere, is actually about as brilliant as limelight.
  • The first, taken alone, might seem to bear out Wilson's theory, but the others show that the penumbra is really very unsymmetrical and much broader on the side towards the limb, apart from anything which perspective may have to say.

How would you define penumbra? Add your definition here.

comments powered by Disqus