# Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 September 20

The Big Corona
Image Credit & Copyright: Alson Wong

Explanation: Most photographs don't adequately portray the magnificence of the Sun's corona. Seeing the corona first-hand during a total solar eclipse is unparalleled. The human eye can adapt to see coronal features and extent that average cameras usually cannot. Welcome, however, to the digital age. The featured picture is a combination of forty exposures from one thousandth of a second to two seconds that, together, were digitally combined and processed to highlight faint features of the total solar eclipse that occurred in August of 2017. Clearly visible are intricate layers and glowing caustics of an ever changing mixture of hot gas and magnetic fields in the Sun's corona. Looping prominences appear bright pink just past the Sun's limb. Faint details on the night side of the New Moon can even be made out, illuminated by sunlight reflected from the dayside of the Full Earth.

Tomorrow's picture: open space

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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