AS 101: THE SUN
.Why does the sun shine?
• 100x the radius of Earth
• 300,000x the mass of Earth
• Luminosity of 4 x 10 W
• 70 % Hydrogen, 28% helium
• Surface = 5800k
• Core = 15 million K
• Pressure is 200 billion times our atmospheric pressure
• Radioactive Decay
o Potassium40 (19p, 21n) ▯Argon40 (18p,22n)
• Nuclear Fission
o Uranium236 ▯Kyrpton92 and Barium141
• Nuclear Fusion
o Unlike Radioactive decay and nuclear fission, nuclear fusion wont decay
from just lying around
MASS MATH – VIA BB
• Mass energy – Radioactive Heat Energy
* 600 billion tons of hydrogen turns in 596 billion tons of helium each second
• Why do they stick together and not repel?
• How come this can only take place in the center of the sun and not in Jupiter’s
atmosphere? AS 101: THE SUN
• What is the Sun like?
o Temperature, Pressure, composition and interior structure
o Why does the sun shine?
What is needed for nuclear fusion to occur?
What does nuclear fusion do in the Sun?
o How does fusion work?
Why do protons stick together to produce energy in the sun?
o As protons get closer, they repel more.
o Strong nuclear force – allows them to attract (only work w/ short
o Nuclei must be 5 x 10 m apart to attract.
o Protons need to move at roughly 5 x 10 in order for them to attract.
Why do we need high temps and high protons for fusion to occur?
o 1 million kelvin isn’t even hot enough
o 10 million kelvin (high enough temp to make things stick)
Extreme Conditions Needed: