Citation Hunt

Leaderboard

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Sunspot:

"

Sunspots have two main structures: a central umbra and a surrounding penumbra. The umbra is the darkest region of a sunspot and is where the magnetic field is strongest and approximately vertical, or normal, to the Sun's surface, or photosphere. The umbra may be surrounded completely or only partially by a brighter region known as the penumbra.[2] The penumbra is composed of radially elongated structures known as penumbral filaments and has a more inclined magnetic field than the umbra.[3] Within sunspot groups, multiple umbrae may be surrounded by a single, continuous penumbra.[citation needed]