Chp 17: lect 2: The Sun Student Copy

The Sun is the most prominent feature in our solar system. It is the largest object and contains approx. _______________ _________________ One hundred and nine Earths would be required to fit across the Sun's disk, and its interior could hold over 1.3 million Earths. The Sun's outer visible layer is called the ______________ and has a temp of __________________This layer has a mottled appearance due to the turbulent eruptions of energy at the surface.

__________________
__________________
__________________
of the Sun. It is here that the temp (15,000,000° C; 27,000,000° F) and pressure (340 billion times Earth's air pressure at sea level) is so intense that nuclear reactions take place. This reaction causes four protons or hydrogen nuclei to fuse together to form one alpha particle or helium nucleus. The alpha particle is about .7 percent less massive than the four protons.

The difference in mass is expelled as ______________ and is carried to the surface of the Sun, through a process known as ______________where it is released as _________________ energy generated in the Sun's core takes a million years to reach its surface. Every second, 700 million tons of hydrogen are converted into helium ashes. In the process 5 million tons of pure energy is released; therefore,as time goes on the __________________________________________.

The ______________ is above the photosphere. Solar energy passes through this region on its way out from the center of the Sun. Faculae and flares arise in the chromosphere. ___________________
_________________ which form above regions where sunspots are about to form. ____________________ of hot gas emerging from sunspot regions. Sunspots are dark depressions on the photosphere with a typical temperature of 4,000°C (7,000°F).
The _________________________
______________ It is in this region that prominences appears.

_______________________________________ that erupt from the upper chromosphere. The outer region of the corona stretches far into space and consists of particles traveling slowly away from the Sun. The corona can only be seen during total solar eclipses.
__________________________________________
http://www.csiro.au/helix/eclipse/live/index.html

The Sun appears to have been active for ______________and has enough fuel to go on for another five billion years or so. At the end of its life, the Sun will start to fuse helium into heavier elements and begin to swell up, ultimately growing so large that it will swallow the Earth. After a billion years as a ______________, it will suddenly collapse into a ______________ -- the final end product of a star like ours. It may take a trillion years to cool off completely.

Sun Statistics
Mass (kg) 1.989e+30
Mass (Earth = 1) 332,830
Equatorial radius (km) 695,000
Equatorial radius (Earth = 1)108.97
Mean density (gm/cm^3) 1.410
Rotational period (days) 25-36*
Escape velocity (km/sec) 618.02
Luminosity (ergs/sec) 3.827e33
Magnitude (Vo) -26.8
Mean surface temperature 6,000°C
Age (billion years) 4.5

Principal chemistry
Hydrogen
Helium
Oxygen
Carbon
Nitrogen
Neon
Iron
Silicon
Magnesium
Sulfur
All others

92.1%
7.8%
0.061%
0.030%
0.0084%
0.0076%
0.0037%
0.0031%
0.0024%
0.0015%
0.0015%

* The Sun's period of rotation at the surface varies from approximately 25 days at the equator to 36 days at the poles. Deep down, below the convective zone, everything appears to rotate with a period of 27 days.
Terms to know for this section:
1. corona 2. radiative zone 3. chromosphere 4. core
5. photosphere 6. nuclear fusion 7. convective zone 8. sunspot