Astronomy Picture of the Day · April 21, 2005

G21.5-0.9: A Supernova's Cosmic Shell

The Astronomy Picture of the Day for April 21, 2005 is “G21.5-0.9: A Supernova's Cosmic Shell,” an image. It is credited to Credit: Heather Matheson & Samar Safi-Harb ( Univ. Manitoba ), CXC , NASA. The original explanation runs about 145 words.

From the explanation

“The picture is lovely, but this pretty cosmic shell was produced by almost unbelievable violence – created when a star with nearly 20 times the mass of the sun blasted away its outer layers in a spectacular supernova explosion .”

— APOD editors, April 21, 2005

Read the full explanation on science.nasa.gov

At a glance

Date: April 21, 2005
Type: Image
Credit: Credit: Heather Matheson & Samar Safi-Harb ( Univ. Manitoba ), CXC , NASA
Copyright: No copyright notice on the entry. Check the credited institution’s own usage rules before reusing it.
Explanation length: About 145 words

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Topics in this entry

Supernovae

Topics are matched from words in the title and explanation.

On this day: April 21 in other years

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Source

Astronomy Picture of the Day, April 21, 2005 — science.nasa.gov/image-article/apod-2005-april-21-g21-5-0-9-a-supernovas-cosmic-shell

Copy taken Oct 28, 2026, 2:39 AM EDT. The image and explanation belong to their creators. OpenOrbit is not affiliated with or endorsed by NASA.