|Last: 10. Stellar Nurseries||Next: 12. The Milky Way and Other Galaxies|
The relentless escape of energy from high-mass stars drives these objects to increasingly extreme stages of nuclear burning. But when the reactions begin to produce iron, the star runs out of nuclear energy sources, and its subsequent explosion spews newly-synthesized elements back into interstellar space.
|Ch. 9-8||When core hydrogen fusion ceases, a main-sequence star becomes a giant|
|Ch. 9-9||Helium fusion begins at the center of a giant|
|Ch. 9-10||As stars evolve, their positions on the H-R diagram shift|
|Ch. 9-11||Globular clusters are bound groups of old stars|
|Ch. 10||HIGH-MASS STARS AND SUPERNOVAE (p. 207)|
|Ch. 10-4||A series of fusion reactions in high-mass stars leads to luminous supergiants|
|Ch. 10-5||High-mass stars violently blow apart in supernova explosions|
|Ch. 10-6||Remnants of supernova explosions can be detected for millennia afterward|
|Ch. 10-7||Supernova 1987A offers a close-up look at a massive star's death|
|Ch. 10-8||Accreting white dwarfs in close binary systems can also explode as supernovae|
This is the remnant of an ordinary low-mass star, known as the Ring Nebula.
Betelgeuse is one of the few stars we have been able to image as anything larger than a point. It is a red supergiant star, and may become a supernova in the next few thousand years.
This high-mass star, ejecting clouds of gas, is near the end of its short life.
The remains of a star whose explosion we saw in 1987 have been analyzed by spreading out the light with with a diffraction grating. The image reveals line emission from oxygen (green), nitrogen & hydrogen (orange), and sulfer (red).
This remnant of a supernova explosion observed in 1054, now called the Crab Nebula, is an expanding cloud of metal-rich gas. In its center is a neutron star spinning 30 times per second.
Wisps of oxygen-rich material (green & blue) from a 3000 year old supernova slam into interstellar gas (red).
Homework 11: Advanced Nuclear Burning, due 11/13.
Quiz 11: Fates of Stars, given 11/08.
Last modified: November 13, 2001