Home » Cosmic Mysteries: What Happens When Stars Die? – BBC News in Chinese

Cosmic Mysteries: What Happens When Stars Die? – BBC News in Chinese

by admin
Cosmic Mysteries: What Happens When Stars Die? – BBC News in Chinese
  • Dana McKenzie
  • (Dana Mackenzie)

image source,NASA

image caption,

The Southern Ring Nebula is actually a shell of gas and dust ejected from a dying star (Credit: Nasa/ESA/CSA/STSCI)

Billions of years later, when the Sun approaches the end of its lifespan and the helium nuclei at its core begin to fuse, it will expand dramatically and become a so-called red giant. After swallowing Mercury, Venus, and Earth, it would become so large that it could no longer hold the outermost layers of gas and dust.

In its glorious finale, it will catapult these outer layers into space, creating a beautiful curtain of light that will glow like neon for thousands of years before disappearing.

The Milky Way is littered with thousands of these splendid remnants, known as planetary nebulae. This is the normal end phase for stars ranging from half the mass of the Sun to eight times the mass of the Sun. More massive stars have a much more violent ending, the kind of explosions known as supernovae. Planetary nebulae come in an amazing variety of shapes, such as the Southern Crab, Cat’s Eye and Butterfly. As beautiful as they are, they are also a mystery to astronomers. How did the Butterfly Nebula emerge from the seemingly unremarkable circular cocoon of a red giant star?

Both observations and computer models now offer an explanation that seemed odd 30 years ago: Most red giant stars have a much smaller companion star hidden in their gravitational pull. This second star is shaped into a planetary nebula by this process, much like a potter shapes a vessel on a turntable.

You may also like

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More

Privacy & Cookies Policy