Why Does The Sun Shine?

Question 1

What did Hipparchus do?

Answer 1

They came up with how we measure stellar brightness on a six point scale; Star Magnitude Scale (Apparent Magnitude)

Lower number = More bright

Question 2

What does a Star’s luminosity depend on?

Answer 2

Size and TEMPERATURE

Question 3

What is the Hertzsprung-Russell Diagram?

Answer 3

Plot that shows us relationship between a star’s temperature and its luminosity.

Question 4

Why does the sun shine?

Answer 4

Nuclear Fusion

Question 5

What is the process of Nuclear Fusion?

Answer 5

1. Hydrogen protons collide to create deuterium.
2. Hydrogen protons collide with deuterium nuclei to produce Helium-3.
3. Helium-3 nuclei collide to make Helium-4.

Question 6

Stars have extreme pressures . . . How do we get to extreme pressures ?

Answer 6

Gravity and pressure increase together as something goes into a ball of gas.

Weight of above material pushes inward (gravity) and supporting pressure acts as outward force.

Question 7

How can a star be stable?

Answer 7

When gravity and pressure are balanced.

Question 8

What is the relationship between Pressure, Density, Temperature, and Depth of a Star?

Answer 8

As you increase in the depth of the center of the star, the pressure, density, and temperature increase.

Question 9

What is the structure of the Sun?

Answer 9

The Core - Center where there is intense heat and temperature; the ideal location for fusion.

At each point within the Sun, the outward push of pressure is balanced by an inward pull of gravity.

The radiated energy from the surface of the Sun balances energy produced in its interior.

Question 10

How do we know that fusion happens in the Sun?

Answer 10

Neutrinos! (Only energy source that lasts long enough and has been only detected coming from Sun)