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When a star like our Sun burns out, it doesn’t go quietly. It has a colorful “last hurrah.” It puffs off glowing clouds of gas. Those form a planetary nebula.
The gases are affected by the spinning and wobbling star. They make shapes that look like a carnival spin-art game. Stars ten times bigger than the Sun go out with a bang. The nuclear furnace suddenly shuts down, and it collapses (falls apart). The collapse is very violent. The star explodes with as much energy as a hundred thousand trillion trillion of the biggest nuclear bombs blowing up at once! This explosion is called a supernova.
◀ Star Corpses
What is left when massive stars explode? Remnants that are crushed by gravity. One of those is a black hole. This object has such strong gravity, no light can escape from it. Another remnant is a neutron star. Its density is 100,000 times greater than steel. We can’t directly see black holes and neutron stars. However, the hot gas around them glows in the X-ray light of a telescope camera. They look like bright points in the Antennae Galaxies (left). These objects will keep giving off energy long after the last star in the universe has burned out. That will be about 10 trillion years from now.
▲ Ant Nebula
This planetary nebula looks like the head and body of an ant. That’s why it’s nicknamed the Ant Nebula. Why is the pattern symmetrical (the same on both sides)? It may be thanks to the gravity of a nearby star pulling on it. Or it could be from the spinning of the dying star itself. Astronomers watch dying Sun-like stars such as this one. It helps them find out what will happen to our Sun.
◀ Supernova Ring
On February 23, 1987, a supernova appeared in the southern sky. It was really bright. It could even be seen without a telescope. The Hubble Space Telescope’s sharp eye caught a glowing ring of gas around the explosion. The ring got brighter again in 2002. That’s when a shockwave from the explosion smashed into the ring. The shockwave made the gases in the ring light up.
▲ Helix Nebula
This nebula looks like a ring at first. But it’s really a trillion-mile-long tunnel. It’s made of material from the central star before it became a white dwarf. The white dot at the center is the hot white dwarf. Its ultraviolet light makes the gases in the helix (spiral) glow.
