Ay [T7] - The Sun Flashcards
What are sunspots, and why do they appear the colour they are?
Dark, cooler regions on the Sun’s surface caused by intense magnetic activity.
Appear as dark patches due to their lower temperatures.
How does doing a pinhole projection of the sun work?
Punch a hole in some paper and hold it pointed at the sun with a piece of paper behind it - an image is formed on the other page
What are the advantages of a pinhole projection?
- Easy
- Cheap
- Safe
- Quick
What is a disadvantage of a pinhole projection?
- Pinhole doesn’t let through much light - small image
What is a use of a pinhole projection?
To view eclipses
How does doing a telescopic projection of the sun work?
Point telescope at sun and place piece of paper or cardboard over eye piece
What are the advantages of doing a telescopic projection?
- Large, clear image
- Easy to set up
What are the disadvantages of doing a telescopic projection?
- Requires a telescope
- Could damage the telescope
What is a use of doing a telescopic projection?
Can see sunspots on the sun
How does using telescopic filters to view the sun work?
Place over a telescope and filter will block most wavelengths but allow certain ones to pass through.
What is an advantage of using telescopic filters?
Most detailed of 3 ways to view the sun
What are the disadvantages of using telescopic filters?
- Expensive
- Filter needs to be perfect
What are the uses of using telescopic filters?
Chromosphere, filaments, prominences
How long is a sunspot cycle on average?
11 years
What happens after one sunspot cycle?
The poles of the horseshoe shaped magnetic fields switch and another cycle begins
How long is the sub cycle of large maximums and small minimums in a sunspot cycle?
22 years
What’s the current theory as to what causes sunspots?
Sunspots caused by horseshoe shaped magnetic fields, buried just below the Sun’s surface lowering the temperature of the surface
Where do sunspots appear on the sun?
Between 30 1/2 degrees north and south latitude (they don’t shift in lat. but do in long.)
Which element is the end result of a proton-proton chain?
Helium
4
He
2
What are the 4 layers of the sun?
Photosphere, Convection Zone, Radiative Zone, Core
What is the temperature of the core of the sun?
15 million K
What is the temperature of the photosphere of the sun?
5,800 K
Where does the Sun produce it’s energy?
The core
What is the process of a proton-proton chain?
2 protons fuse to form a deuterium, an isotope of hydrogen. One of the protons turns into a neutron. A neutrino and positron are emitted in the process.
Another proton fuses with deuterium to form helium-3.
Two helium-3 nuclei fuse to form helium-4 and two protons. This means that these 2 protons can go to be fused in another cycle.
Repeat.
What type of reaction between particles occurs in the Sun’s core?
Nuclear fusion
What is the corona and what is it made of?
The outermost region of the Sun’s atmosphere, made of plasma
What is the temperature of the corona?
Approximately 2 million K (much hotter than surface of sun)
How far into space does the corona extend?
Approximately 8.2 million km
What is the chromosphere and what is it made of?
A thin layer of plasma that lies between the Sun’s photosphere and the corona
What is the temperature of the chromosphere at the beginning?
5,800 K
How far into space does the chromosphere extend?
At least 2,000km
Why is the chromosphere named that?
It’s red colour, which is due to it being mainly made of plasma
What is the name of the belts of the Earth’s magnetic field, and what do they do?
Van Allen belts
Deflect the solar wind away from earth
What is the effect of solar wind on comets?
Causes the direction that the ion tail points in
What is the cause of solar wind?
The release of mainly charged H+ particles from the corona
What are coronal mass ejections?
Large amounts of solar wind being released from the corona
Draw a diagram of the Van Allen Belts
What is the effect of solar wind on aurora?
Coronal mass ejections being pulled to the poles of the earth by the magnetic field
