Penumbra (disambiguation)

The penumbra is the part of a shadow where the light source is only partially blocked.

Penumbra may also refer to:




  • Penumbra (law), a metaphor for rights implied in the United States Constitution
  • Penumbra (medicine), surviving tissue at the margin of an ischemic event (such as a stroke) which is in danger of hypoxia and subsequent cell death
  • Penumbra (Sun), the ring-shaped semi-bright region of a sunspot that surrounds the darker umbra
  • Penumbral lunar eclipse, an eclipse that occurs when the Moon passes through the Earth's penumbra
  • Billbergia 'Penumbra', a hybrid cultivar of the genus Billbergia in the Bromeliad family

See alsoEdit