Topic 10 Flashcards
Name 2 methods of safely observing the Sun
Telescopic projection- point telescope at Sun and use eyepiece to project the image of the Sun onto card
(DO NOT LOOK IN THE TELESCOPE
H-alpha filter- H-alpha is a specific band of wavelength in the SUn’s light spectrum observing this band of wavelength allows us to safely see emissions and the sun’s surface, the filter focuses on the h-alpha wavelengths and filters out the others
Name the internal divisions of the Sun
Starting from centre:
-Core
-Radiative and Convection zones
-Photosphere
Name the components of the solar atmosphere
Chromosphere
Corona
How hot are the core, radiative and convection zones, and photosphere
15,000,000 degrees K, 2,000,000-6,000 degrees K, 5,800 degrees K
WHat happens at the core
Where the sun produces energy.
It is so hot the SUn is able to react Hydrogen nuclei into Helium via nuclear fusion
What happens at the radiative and convection zones
Light photons and heat pass through these regions. In the radiative zone photons are scattered by electrons and in the convection zone, thermal energy is transferred by rising currents of hot plasma
What happens at the photosphere
This is the surface layer of the SUn that we are able to see. Features of the photosphere include a process called granulation- these are circular areas with a thin darker area around them. Sunspots are also visible in the photosphere
What is the chromosphere (sphere of colour)
The chromosphere
What are the brighter regions of granules
The top of convection currents, which are hot plasma rising
What is the SUn’s core
an extremely hot environment, which is so hot that the Sun can react hydrogen nuclei into Helium through nuclear fusion
What is the Sun’s radiative zone?
Photons are scattered and emitted by electrons
What is the SUn’s convection zone
Thermal energy is transferred by rising currents of hot plasma
What is the photosphere
The layer of the Sun we can see
-granulation happens here which is circular areas with a thin darker area around them
-the granules are the tops of convection currents
What is the chromosphere
the lower region of the Sun’s atmosphere
-Only briefly observed during a solar eclipse as a bright rim around the Sun
What is the corona?
Upper region of the Sun’s atmosphere, made of gases expelled from the Sun
-best observed during a solar eclipse where it appears as a ‘halo’
-it emits x-rays
-it generates high energy particles which interact with the magnetic field of the Sun
->some of these particles are pulled back towards the SUn while others are so energised they fly out of the corona at high speeds to form the SOlar wind
What is the solar minimum
When the least and most sunspots are, this is an 11 year cycle which forms half of a 22 year cycle of solar activity, after the minimum and maximum is reached, the polarity of the magnetic field reverses
What is nuclear fusion
At high temperatures, hydrogen nuclei fuse to form helium
-through the proton-proton chain
-releasing lots of energy
What are sunspots?
> Areas on the photosphere that are cooler than the surrounding area and appear darker as a result
They have a high magnetic field strength which keeps internal heat from reaching the areas
SUNSPOT UMBRA: 4000K
SUNSPOT PENUMBRA: 5600K
What are the origins of SUnspots
caused by changes in the Sun’s magnetic field.
Coronal loops are ejected and drawn back to the Sun.
-They can build up to form prominences when they land they ‘puncture’ the chromosphere and decrease the temperature
-They can last from several hours to months
WHat is evidence for the solar cycke
Sunspots are good evidence for what the SUn goes through every 11 years.
-It can be visualised using the butterfly diagram
-THe more sunspots, the more heat
-THe more sunspots mean the more active the Sun is
How can we observe the rotation of the Sun?
We can observe the rotation of the SUn by recording the speed of Sunspots across the photosphere
WHy doesn’t the Sun rotate like a terrestrial planet, what are the times of rotation at the equator and pole?
The Sun is a ball of gas and plasma so doesn’t rotate like a terrestrial planet.
Its poles rotate slower
equator- 25 days
poles- 36 days
What is the Solar wind?
Charged particles are produced by the corona at high velocities
-THe magnetic field draws some particles back to the Sun
-others gain enough energy to overcome the Sun’s gravity and are ejected into space- becoming solar wind
