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  2. Umbra, penumbra and antumbra - Wikipedia

    en.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra

    An observer in the penumbra experiences a partial eclipse. An alternative definition is that the penumbra is the region where some or all of the light source is obscured (i.e., the umbra is a subset of the penumbra). For example, NASA's Navigation and Ancillary Information Facility defines that a body in the umbra is also within the penumbra. [2]

  3. Wilson effect (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Wilson_effect_(astronomy)

    Diagram of the Wilson effect. The umbra is the darker inner circle and the penumbra is the lighter ring around the umbra. In astronomy, the Wilson effect is the perceived depression of a sunspot's umbra, or center, in the Sun's photosphere. The magnitude of the depression for the umbra is between 500 and 1000 km, with an average of 600 km. [1]

  4. Sunspot - Wikipedia

    en.wikipedia.org/wiki/Sunspot

    The umbra may be surrounded completely or only partially by a brighter region known as the penumbra. [23] The penumbra is composed of radially elongated structures known as penumbral filaments and has a more inclined magnetic field than the umbra. [24] Within sunspot groups, multiple umbrae may be surrounded by a single, continuous penumbra.

  5. What is an umbra? A penumbra? Here's some terms to know ... - AOL

    www.aol.com/umbra-penumbra-heres-terms-know...

    What is the penumbra during an eclipse. The second shadow is called the penumbra. According to timeanddate.com, the penumbra is the lighter outer part of the moon’s shadow. It is the portion of ...

  6. Penumbra (medicine) - Wikipedia

    en.wikipedia.org/wiki/Penumbra_(medicine)

    In pathology and anatomy the penumbra is the area surrounding an ischemic event such as thrombotic or embolic stroke. Immediately following the event, blood flow and therefore oxygen transport is reduced locally, leading to hypoxia of the cells near the location of the original insult.

  7. Earth's shadow - Wikipedia

    en.wikipedia.org/wiki/Earth's_shadow

    Since Earth's diameter is 3.7 times the Moon's, the length of the planet's umbra is correspondingly 3.7 times the average distance from the Moon to the Earth: roughly 1,400,000 km (870,000 mi). The width of the Earth's shadow at the distance of the lunar orbit is approximately 9000 km (~ 2.6 lunar diameters), which allows people of the Earth to ...

  8. Wikipedia:What is fringe? - Wikipedia

    en.wikipedia.org/wiki/Wikipedia:What_is_fringe?

    One part of its shadow is called the penumbra. The penumbra is the region where the light from the source is partly blocked; it runs from full light at one side to full shadow at the other. Another part of the shadow is called the umbra. The umbra is the region where the light is completely blocked.

  9. File:Umbra01.svg - Wikipedia

    en.wikipedia.org/wiki/File:Umbra01.svg

    The umbra is the dark inner shadow and the penumbra is the faint outer shadow. The path of totality is the path that is travelled by the umbra and anyone located on it can see the total eclipse. Anyone who is in the vicinity of the umbra in the penumbra is able to see the partial eclipse.