Download Milky Way

The sun
Aim: What are some characteristics of the
sun?
I. Sun – the closest star to earth.
a. Star – creates its own energy by fusing
hydrogen into helium (nuclear fusion).
b. The sun is an average star and can be
found in the middle of the HertzsprungRussell diagram. (p. 15 of ESRT)
1. Hertzsprung-russell diagram –
Groups stars by color (an indication of
temperature) and by how much light
they give off.
What is the color of the coolest stars?
Hottest stars?
C. Some interesting sun facts
1. Mass = 300,000 times the earth
2. Surface temperature = 9900oF
3. Core temperature = 27,000,000oF
4. Composition = 71% H, 27% He,
and 2% heavier elements.
Solar Prominence
Aurora
II. Other Astronomical Terms
A. Galaxy - a huge body of stars and other
matter in space. Ex: our Sun is one of
roughly 100 billion stars in the Milky
Way.
B. Milky Way – a spiral galaxy. Our solar
system is located in the spiral arm of the
Milky Way, far from the center of it.
Approximately 150, 000 light years
across!
How do we know that the universe is
expanding?
Red Shift (Doppler Shift) – light is traveling
away from us. Long waves.
Blue Shift – light is traveling towards us. Short
waves.
Electromagnetic Spectrum
The Milky Way
The Milky Way
100,000 Light Years across