The Sun?

1. The Sun?

2. The Sun is a star! There are an incredible amount of stars in the universe. Yay! What is a star…? A star is a huge sphere of very hot, glowing gas. Stars produce their own light and energy by a process called nuclear fusion. Fusion happens when lighter elements are forced to become heavier elements. When this happens, a tremendous amount of energy is created causing the star to heat up and shine. Stars come in a variety of sizes and colors. Our Sun is an average sized yellowish star. Stars which are smaller than our Sun are reddish and larger stars are blue. Useful Links: http://science.nationalgeographic.com/science/space/universe/stars-article/ http://www.universetoday.com/24351/what-is-a-star/ http://imagine.gsfc.nasa.gov/docs/science/know_l2/stars.html

3. The Sun – Our Star • One of many stars in the Milky Way, but extremely important to us…why? • Energy, understanding • A ball of gas, which can be generally thought of as having four “layers”: • Solar interior, visible surface (photosphere) and two atmospheric components (chromosphere and corona)

7. Solar Activity Sunspots: dark regions on the Sun that are slightly cooler than surrounding surface, and are associated with very strong magnetic activity.

8. Sunspots • Observed throughout antiquity (try looking at the sun at its lowest point in the sky, or through a cloud bank and you can occasionally see them unaided) • Deduction of Solar Rotation rate and differential rotation nature from sunspot observation • Dark spot? Not really. Many X brighter than Full Moon. Its relative.

9. Sunspots

11. Prominences/Flares • http://www.space.com/25287-major-solar-flare-eruption-video.html • http://www.space.com/25291-sun-sticks-out-a-tongue-of-super-heated-plasma-video.html • http://youtu.be/wisdfag6WIQ

12. Prominences/Flares • Flares are massive eruptions from the surface of the Sun resulting in huge amounts of charged particle energy ejected into space (CMEs – Coronal Mass Ejections) • Threating to astronauts, damaging to communication systems • Kill shot? Radio/X-Ray/UV radiation • Prominences are large looping structures of solar material tapped by magnetic fields.

19. Aurora Borealis/AustralisColors

20. Solar Interior

22. Missing Matter -> Energy • Matter is converted to energy according to Einstein's famous formula: • E = mc2 • c = speed of light (3x108m/s) • M = mass (kg) • E = energy (Joules [J]) • A Joule is a unit of energy equivalent to the energy needed to apply a force of 1 Newton through a distance of one meter.

23. How much energy in matter?

24. The equivalent of energy that would be produced by burning 1000 tons of coal!!

25. Solar Fusion • 4 million tons of Hydrogen converted to energy every second in Solar core! • This consumes 600 million tons of Hydrogen “fuel” every second! • How long can such fuel consumption keep up before the Sun run’s out? • At present rate: about another 100 billion years!! Conclusion?

26. Solar Fusion • The Sun can last for a long time, however it will not last for another 100 billion years • In about 4.5 billion years, the Sun will swell into a Red Giantstar. • This will happen b/c the Sun has run out of Hydrogen fuel in its core, resulting in less outward pressure and gravitational contraction, leading to increased pressure/temp. and fusion of heavier elements.