Chp 4: The Sun Flashcards
The Sun is a ___ ____ star
main sequence
What is the structure of the Sun (name the layers)
(outer) corona, chromosphere, photosphere, convection zone, radiation zone, core
What is the most common element in the Sun?
hydrogen
What is the purpose of NASA’s Genesis mission and how was this accomplished
NASA’s Genesis mission set out to capture particles of the solar wind and return them for study on Earth. It traveled to an area in space between Earth and the Sun where the gravity of the two bodies is balanced.
- it collected solar wind particles for more than two years from an area in space far from the interfering effects of any planet.
oblate
an equatorial diameter greater than that between the poles of rotations (width > height)
astronomical unit
the mean average distance between the Sun and Earth
chromosphere
is the irregular layer of gases that extends up and away from the photosphere
photosphere
(visible outer layer of a star) represents the depth within that gas at which we can see no deeper toward the core.
corona
the outermost region of the Sun’s atmosphere
Spectroscopy
- the measurement and analysis of energy spectra to determine the composition of matter.
- The device often used for such analysis is a spectrometer or a spectrograph, which records the spectrum of light emitted (or absorbed) by a given material, where the light can be used to determine the chemical composition of a substance because particular elements emit unique and characteristic wavelengths of energy.
What was surprising about the results of the Genesis mission?
It turned out that the isotopic compositions of oxygen and nitrogen implanted in the wafers are significantly different to those in most of the Solar System objects for which we have measurements.
What is a Sunspot? Why are they black?
sunspot = a region of the Sun’s photosphere marked by lower than average temperature, thus appearing black.
Does the Sun have a magnetic field?
yes, has to do with the interaction of the unique properties of matter in the different layers inside the Sun.
How often does the Sun’s magnetic field usually flip or how long does a solar cycle last?
-switch happens almost like clockwork every 11 years or so (the complete 22 year cycle is referred to as a ‘solar cycle’)
What is a solar cycle?
- The Sun’s magnetic field goes through a cycle, called the solar cycle.
- Every 11 years or so, the Sun’s magnetic field completely flips. This means that the Sun’s north and south poles switch places.
Does the solar wind reach the Earth?
- The interaction of the charged particles (electrons and protons) of the solar wind with a magnetic field (magnetosphere) (remember that charged particles always react with a magnetic field).
- The reaction essentially protects most of Earth’s surface from devastating bombardment by the solar wind – but not the poles!
plasma
an ionized gas made up of a mixture of electrons and protons
What are two effects of magnetic storms on Earth are caused by solar flares?
- They can disrupt over-the-horizon radio communication
- degrade the accuracy of GPS,
- damage satellite electronics
- alter satellite orbits
- interfere with directional drilling for oil and gas.
How does the aurora borealis form?
- On their way to Earth’s magnetic poles, the solar particles interact with the molecules of gas in the upper atmosphere
- the result is emission of a light photon (which is visible) from each collision.
- Lots of collisions means lots of light photons, so during solar flares there is a lot of light produced.
- in the north they are the aurora borealis,and in the south they are the aurora australis.
What are the stages of the Sun from birth to death?
Birth: Nebular Hypothesis
- as the last of the inner hydrogen fuel is consumed (in about 5 billion years from now), the Sun will expand into a red giant.
- This expansion accompanies the first use of helium as fuel – replacing hydrogen – and the helium fuses to form carbon and oxygen. it will blow off its outer envelope into space, leaving its core to cool and become a white dwarf, and ultimately, when it stops glowing altogether, end up as a black dwarf.
magnetosphere
The magnetic field volume around a body like Earth, (which generates a magnetic field)
The most abundant element in the Sun is ____.
Hydrogen
The _____ is the visible outer layer of a star.
Photosphere
Name 3 facts about the sun
- It is oblate in shape
- Its surface is 5,800K
- Its diameter is about 109 times that of Earth
