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2015 July 14

The West Limb

The Hinode X-ray Telescope took this amazing portrait of the sun on 2015 July 1 at 17:26 UT using the Al-mesh filter. Large loops, rings, and even a wishbone can be seen off the west limb. Each of these shapes provide clues about what lies below.

The wishbone shape is also known as a helmet streamer. They form above active regions and can extend far away from the sun. The bright streak forming the spine of the wishbone is probably a current sheet. Current sheets store energy that drives magnetic reconnection.

Below the wishbone are a set of concentric rings forming a coronal cavity. Once mistaken for an alien ship, these rings actually sit above a filament channel. They are a quiet sun feature and are surprisingly stable lasting several solar rotations. However, their quiet nature is deceiving because when they erupt they can cause havoc at Earth with a coronal mass ejection.

Keywords: Limb, Current Sheet, Cavity
Filters: Al_mesh

(Prepared by Patricia Jibben)

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