Called the Bubble Nebula, this eerie, translucent sphere is created
by fierce winds from a superhot star 40 times the size of our sun.
Moving at nearly 4.5 million miles per hour, stellar winds whip the
cloud of gas around the star into a near-perfect bubble, which stands
out from the rest of the more stationary gas in this emission nebula.
Located 7,100 light-years from Earth in the constellation Cassiopeia,
the bubble is about 6 light-years in diameter and glows pink because of
the red, hot gas that surrounds it.
