Updated: Dec 3, 2021
The Bubble Nebula is a beautiful emission nebula discovered by William Herschel in 1787. It lies about 10,000 light-years away in the constellation Cassiopeia. Obviously, NGC 7635 got its nickname from the shape of its expelling gas, forming what appears to be a bubble in space. The visible gas is escaping from the center of the nebula, where a star 45 times more massive than our sun lights up its surrounding area.
The photo on the right was taken by the Hubble Space Telescope to celebrate its 26th birthday.