Billions and Billions.com

The Bubble NGC 7635 in Cassiopeia

The Bubble is an expanding shell of glowing gas and dust surrounding a hot, massive star- BD+602522. Called Wolf-Rayets these stars are 20 times more massive than our Sun and number only 300 in our galaxy. The fierce stellar wind forces the surrounding gas into this amazing shape as the intense starlight ionizes it, causing it to glow in Hydrogen alpha light. Often classed as a planetary nebula, it is atypical of the family; and is likely a supernova remnant. The nebula is 10 light-years across, more than twice the distance from Earth to our nearest star! NGC 7635 is estimated to be about 11,300 light-years away from us. The Bubble is actually the smallest of three bubbles surrounding the massive star, and part of the gigantic network S162 created with the help of other massive stars.