1. Stellar Fusion

2. http://www. nasa. gov/images/content/171925main_heliolayers_label_516

3. FUSION: hydrogen to helium
Our Sun is 75% H2, 24% He, and 1% heavier elements.
The Sun produces energy by FUSION: by combining hydrogen atoms to make helium.

4. E = mc2 STEP 1: 1H + 1H -> 2H + + STEP 2: 2H + 1H -> 3He
STEP 3: 3He + 3He -> 4He H
OVERALL: 4 1H -> 4He + 2+ + energy
How much energy? About 600 million kcal per mole of helium produced! How long would that “fuel” YOU?

5. helium to carbon
While the Sun fuses H to He there is a balance between gravity pulling the Sun’s contents inward and the energy produced pushing the Sun’s contents outward.
When most of the Sun’s H fuel is exhausted the balance will tip, and the Sun will contract. This will heat up the core until its hot enough to “ignite” the helium. The Sun will then expand to a new size as it fuses He into C.

6. http://www. physics. hku

7. more E = mc2 STEP 1: 4He + 4He -> 8Be STEP 2: 4He + 8Be -> 12C
OVERALL: 3 4He -> 12C
This process produces less energy than the fusion of H into He. This can be seen in the stars, which are red giants. “Red hot” is cooler than our Sun’s “yellow hot” … or massive star’s “blue hot”.

8. Nuclear Binding Energy
Fusion <- -> Fission
Stars can produce energy by fusion only up to 56Fe … beyond that fusion is “endothermic.”

9. (make elements > 56Fe)
(make elements > 56Fe)

10. Nebulae Crab Nebula: supernova seen in AD 1054
This composite image of the Crab Nebula was assembled from 24 individual exposures taken with the NASA Hubble Space Telescope’s Wide Field and Planetary Camera 2 in October 1999, January 2000, and December It is one of the largest images taken by Hubble and is the highest resolution image ever made of the entire Crab Nebula.
CHANDRA wb site

11. Supernova c. 1870 on Earth - the most recent in our galaxy
he expanding remains of a supernova explosion in the Milky Way are shown in this composite image, on the left, of the supernova remnant G NASA's Chandra X-ray Observatory image obtained in early 2007 is shown in orange and the radio image from NRAO's Very Large Array (VLA) from 1985 is in blue. The difference in size between the two images gives clear evidence for expansion, allowing the time since the original supernova explosion (about 140 years) to be estimated.
This makes the original explosion the most recent supernova in the Galaxy, as measured in Earth's time-frame (referring to when events are observable at Earth). Equivalently, this is the youngest known supernova remnant in the Galaxy (140 years old), easily beating the previous record of about 330 years for Cassiopeia A. The rapid expansion and young age for G was recently confirmed by a new VLA image obtained in early 2008.
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G :
Discovery of Most Recent Supernova in Our Galaxy G
Credit: X-ray (NASA/CXC/NCSU/S.Reynolds et al.); Radio (NSF/NRAO/VLA/Cambridge/D.Green et al.); Infrared (2MASS/UMass/IPAC-Caltech/NASA/NSF/CfA/E.Bressert)
JPEG (386.7 kb) Tiff (23 MB) PS (1.2 MB)
The expanding remains of a supernova explosion in the Milky Way are shown in this composite image, on the left, of the supernova remnant G NASA's Chandra X-ray Observatory image obtained in early 2007 is shown in orange and the radio image from NRAO's Very Large Array (VLA) from 1985 is in blue. The difference in size between the two images gives clear evidence for expansion, allowing the time since the original supernova explosion (about 140 years) to be estimated.
Radio and X-rayMore images
The original supernova explosion was not seen in optical light about 140 years ago because it occurred close to the center of the Galaxy, and is embedded in a dense field of gas and dust. This made the supernova about a trillion times fainter, in optical light, than if it had been unobscured. However, X-rays and radio waves from the resulting supernova remnant easily penetrate this dust and gas.
CHANDRA web site

12. Black Hole X-ray”center”
The accompanying illustration (top) depicts how such an event may have occurred. A close encounter with another star put the doomed star (orange circle) on a path that took it near a supermassive black hole. The enormous gravity of the giant black hole stretched the star until it was torn apart. Because of the momentum and energy of the accretion process, only a few percent of the disrupted star's mass (indicated by the white stream) was swallowed by the black hole, while the rest of was flung away into the surrounding galaxy.
Observations with Chandra (lower left image) and XMM-Newton, combined with earlier images from ROSAT, confirmed that a powerful X-ray outburst had occurred in the center of the galaxy RX J , which appears normal in a ground-based optical image (lower right, with the white circle defining the location of the Chandra image). This X-ray outburst, one of the most powerful ever detected in a galaxy, was caused when gas from the disrupted star was heated to multimillion degree temperatures as it fell toward the black hole.
he tidal disruption of a star is estimated to occur about once every ten thousand years in a typical galaxy. As astronomers accumulate observations of thousands of galaxies, many more of these events should be detected.

13. artificial fusion Produces more energy per pound of fuel than fission
Creates far less radioactive waste products
Uses much cheaper fuel (H) than fission (U or Pu)
So ….. WHY NOT?
TOKOMAK REACTOR