Chp 4: The Sun

Question 1

The Sun is a ___ ____ star

Answer 1

main sequence

Question 2

What is the structure of the Sun (name the layers)

Answer 2

(outer) corona, chromosphere, photosphere, convection zone, radiation zone, core

Question 3

What is the most common element in the Sun?

Answer 3

hydrogen

Question 4

What is the purpose of NASA’s Genesis mission and how was this accomplished

Answer 4

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.

Question 5

oblate

Answer 5

an equatorial diameter greater than that between the poles of rotations (width > height)

Question 6

astronomical unit

Answer 6

the mean average distance between the Sun and Earth

Question 7

chromosphere

Answer 7

is the irregular layer of gases that extends up and away from the photosphere

Question 8

photosphere

Answer 8

(visible outer layer of a star) represents the depth within that gas at which we can see no deeper toward the core.

Question 9

corona

Answer 9

the outermost region of the Sun’s atmosphere

Question 10

Spectroscopy

Answer 10

• 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.

Question 11

What was surprising about the results of the Genesis mission?

Answer 11

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.

Question 12

What is a Sunspot? Why are they black?

Answer 12

sunspot = a region of the Sun’s photosphere marked by lower than average temperature, thus appearing black.

Question 13

Does the Sun have a magnetic field?

Answer 13

yes, has to do with the interaction of the unique properties of matter in the different layers inside the Sun.

Question 14

How often does the Sun’s magnetic field usually flip or how long does a solar cycle last?

Answer 14

-switch happens almost like clockwork every 11 years or so (the complete 22 year cycle is referred to as a ‘solar cycle’)

Question 15

What is a solar cycle?

Answer 15

• 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.

Question 16

Does the solar wind reach the Earth?

Answer 16

• 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!

Question 17

plasma

Answer 17

an ionized gas made up of a mixture of electrons and protons

Question 18

What are two effects of magnetic storms on Earth are caused by solar flares?

Answer 18

• 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.

Question 19

How does the aurora borealis form?

Answer 19

• 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.

Question 20

What are the stages of the Sun from birth to death?

Answer 20

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.

Question 21

magnetosphere

Answer 21

The magnetic field volume around a body like Earth, (which generates a magnetic field)

Question 22

The most abundant element in the Sun is ____.

Answer 22

Hydrogen

Question 23

The _____ is the visible outer layer of a star.

Answer 23

Photosphere

Question 24

Name 3 facts about the sun

Answer 24

• It is oblate in shape
• Its surface is 5,800K
• Its diameter is about 109 times that of Earth