|This nebula is along the northeast circumference of a very large molecular cloud called the Cepheus Bubble. This is a bubble of gas and dust that is around 500 light years across and approximately 2,700 light years away. From our vantage point on earth, this bubble extends across 10 degrees of sky! The bubble was formed only 10-20 million years ago inside one of the outer spiral arms of our galaxy. Stars in the center of the bubble formed and the most massive ones quickly exploded marking the origin of this molecular cloud. The subsequent compression wave of gas trigged new star formation- especially along the edges of the bubble where the gas is most dense. SH2-140 is one such region. Another more famous area along the southern rim of the bubble is IC 1396 (SH2-131).|
|L R G B color production was used to create this image.||
Minimum credit line: Tom Smith/Adam Block/NOAO/AURA/NSF
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