Astr 2 Test 2 Dartmouth College 14X, Lecture (7-1-2014): The Sun Part 1

Front 1

Sun's mean distance to Earth?

Back 1

93 million miles or 150 km = 1 AU

Front 2

Sun's light travel time to Earth?

Back 2

8.32 minutes

Front 3

Maximum Distance from Sun to Earth

Back 3

152,000,000 km

Front 4

Minimum Distsance from Sun to Earth

Back 4

147,000,000 km

Front 5

Mean angular diameter

Back 5

32 arcminutes

Front 6

Radius of the Sun in km

Back 6

696,000 km

Front 7

Radius of the Sun in Earth radii

Back 7

109 Earth radii

Front 8

Mass of the Sun in kg

Back 8

1.981x10**30 kg

Front 9

Mass of the Sun in Earth's Mass

Back 9

3.33 x 10**5 of Earth Masses, or 333,000 Earth's Mass

Front 10

How old is the Sun?

Back 10

greater than 4.2 billion years; oldest meteorites are at least 4.5 ~ 4.6 Gyr

Front 11

What does Gyr stand for?

Back 11

1 billion year = 1 Gyr = Ga

Front 12

How do you date the Sun?

Back 12

Date geological formations and rocks with various geochronometrical methods using radioactive decay properties

Front 13

Uranium 238 has a half life of _____ years and turns into _____.

Back 13

Uranium 238 has a half life of 4.5 billion years and turns into Lead 206.

Front 14

Uranium 235 has a half life of ______ years and turns into ______.

Back 14

Uranium 235 has a half life of 713 million years and turns into Lead 207.

Front 15

Thorium 232 has a half life of ______ years and turns into ______.

Back 15

Thorium 232 has a half life of 13.9 billion years and turns into Lead 209.

Front 16

Plutonium 241 has a half life of ______ years and turns into ______.

Back 16

Plutonium 241 has a half life of 2.4 million years and turns into Bismuth 209.

Front 17

The first guess for the solar energy source in the early 18th century was:

Back 17

Chemical processes (i.e. burning fuel)

Front 18

Maximum burning time of 'burning' fuel guess in the early 18th century was

Back 18

only ~10,000 years

Front 19

Another first guesses at the solar energy source in the mid-1800's was:

Back 19

Gravitational energy, also known as the Kelvin-Helmholtz mechanism.

Front 20

What is the Kelvin-Helmholtz mechanism?

Back 20

A guess for the solar energy source made in the mid-1800's; it stipulated that the solar energy came from gravitational energy and that the slow contraction of Sun released energy and heated the gas up and the energy radiated into space

Front 21

What is the maxium contraction time for the Kelvin-Helmholtz mechanism in the mid-1800s?

Back 21

25 million years; the gravitational energy from the contraction of the Sun was only important at very early stage (birth of Sun)

Front 22

What was the basic problem faced in trying to explain an energy source for the Sun?

Back 22

We needed more energy released per atom.

Front 23

Who and which equation helped to explain the solar energy source?

Back 23

Albert Einstein: E=mc**2; the equation says mass and energy are equivalent

Front 24

Why was the equation E=mc**2 useful in explaining the solar energy source?

Back 24

"c" or the speed of light is a very large number (300,000 km/s)

Front 25

What is the 'correct' explanation for the solar energy source?

Back 25

Thermonucelar fusion, i.e. turning mass into energy

Front 26

Thermonuclear fusion transforms _____ into _____

Back 26

Thermonuclear fusion transforms Hydrogen into Helium.

Front 27

What is the mass balance from transforming Hydrogen into Helium?

Back 27

4 Hydrogen atoms (6.693 x 10**-27 kg) --> 1 Helium atom (6.645 x 10**-27 kg); Mass lost: 0.048 x 10**-27 kg

Front 28

Fusing 1 kg of Hydrogen relases th same energy as burning _____ metric tons of coal

Back 28

Fusing 1 kg of Hydrogen relases th same energy as burning 20,000 metric tons of coal

Front 29

How much hydrogen must be converted to give soalr luminosity?

Back 29

600 million metric tons per second

Front 30

600 million metric tons of hydrogen per soecond must be converted to give solar luminosity, but Sun has enough fuel for at least _____ years.

Back 30

Sun has enough fuel for at least 9 billion years.

Front 31

What does "thermo" mean in thermonuclear fusion?

Back 31

"thermo" in thermonucelar fusion refers to the enormous temperature needed for nuclei to fuse

Front 32

Why is it difficult to get nuclei to fuse?

Back 32

Due to electric repulsion of the nuclei of atoms

Front 33

What does 'fusion' stand for in thermonuclear fusion?

Back 33

"fusion" in thermonuclear fusion stands for the putting together of hydrogen (H) atoms to make helium (He) atoms

Front 34

What does 'nuclear' stand for in thermonuclear fusion?

Back 34

'Nuclear' in thermonuclear fusion stands for the nuclei of atoms which are involved in creating helium atoms from hydrogen atoms.

Front 35

The Sun is powered by __________.

Back 35

The Sun is powered by nuclear fusion.

Front 36

What does "fusion" mean?

Back 36

The "merging" of 2 or more atomic nuclei to form a bigger nucleus.

Front 37

In Sun, _____ nuclei collide and merge to form _____ nuclei.

Back 37

In Sun, hydroen nuclei collide and merge to form helium nuclei.

Front 38

The actual process in the Sun of nuclear fusion is called the "_______________."

Back 38

The actual process in the Sun of nuclear fusion is called the "proton-proton chain (p-p chain)."

Front 39

Nuclear fusion, or p-p chain is often called __________.

Back 39

Nuclear fusion, or p-p chain is often called hydrogen burning.

Front 40

Describe the first step in the process of proton-proton chain (p-p chain).

Back 40

1) Proton (p) + proton (p) --> deuterium (D) + nutrino (v) + positron (e+) [and e+ and e --> 2*gamma]

Front 41

Describe the second step in the process of proton-proton chain (p-p chain).

Back 41

2) deuterium (D) + p (positron) --> 3_He + gamma (Run this step twice, yielding 2 helium atoms)

Front 42

Describe the third step in the process of proton-proton chain (p-p chain).

Back 42

Take the 2 3_He atoms from the previous step; 3) 3_He + 3_He --> 4_He + 2p (2*proton)

Front 43

Summarize the basic p-p chain:

Back 43

4p --> 4_He + neutrinos + lots of energy!

Front 44

Which step in the p-p chain process is the most difficult?

Back 44

Step 1 (proton (p) + proton (p) --> deutretrium (D) + neutrino (v) + positron (e+) [and e+ + e- --> 2y], is the most difficult so they have have to smash together going very fast.

Front 45

The Solar surface temperature is (in Kelvins)

Back 45

~5800 K

Front 46

Temperature required for fusion is (in Kelvins)

Back 46

~15 million K

Front 47

Fusion can only occur at __________.

Back 47

Fusion can only occur at core of the Sun

Front 48

Observational fact 1: The Sun does/does not change size over long period of the time and keeps is shape quite well/badly. (Circle one)

Back 48

The Sun does not change size over long periods of time, and keeps its shape quite qwell.

Front 49

Principle of Hydrostatic Equilibrium means that:

Back 49

Pressure and gravity maintain a balance.

Front 50

The principle referring to the fact that pressure and gravity maintain a balance.

Back 50

Principle of Hydrostatic Equilibrium means that pressure and gravity maintain a balance.

Front 51

Principle of Hydrostatic Equilibrium happens because gas pressure/gravity act from within and gas pressure/gravity presses down. (Circle one)

Back 51

Principle of Hydrostatic Equilibrium happens because gas pressure (coming from below the slab of solar material) act from within, pressing up, and gravity (from the gases above the slab of the solar material and the weight of the slab) presses down.

Front 52

Conclusions from the Principle of Hydrostatic Equilibrium:

Back 52

pressure and temperature increases with depth

Front 53

Where does the gas pressure and gravity in the Sun come from?

Back 53

Equilibrium between pressure and gravity (Principle of Hydrostatic Equilibrium) in the Sun happens because gas pressure coming from below the slab of solar material act from within, pressing up the slab, and gravity from the gases above the slab of the solar material and the weight of the slab presses down on the slab.

Front 54

Observational Fact 2: The Sun does/does not heat up or cool down over long periods of time and keeps its temperature quite well/badly. (Circle one)

Back 54

The Sun does not heat up or cool down over long periods of time and keeps its temperature quiet well.

Front 55

Principle of Themal Equilibrium says that

Back 55

energy generation and energy transport maintain a balance.

Front 56

The three modes of energy transport are:

Back 56

1) Conduction; 2) Convection; 3) Radiative

Front 57

Conduction mode of energy transport is very efficient/inefficient for gases. (Circle one)

Back 57

Conduction is very inefficient for gases.

Front 58

Convection mode of energy transport is '_______ of fluids,' or ______ of hot gases.

Back 58

Convection is 'circulation of fluids,' or upwelling of hot gases.

Front 59

Radiative mode of energy transport is ______ carrying away energy.

Back 59

Radiative mode of energy transport is photons carrying away energy.

Front 60

The zones in the Sun (starting from the center):

Back 60

1) Core 2) Radiative Zone, 3) Convection Zone, 4) Photosphere, 5) Chromosphere, 6) Corona, 7) Solar Wind

Front 61

The radius of the core of the Sun is below ______ km.

Back 61

The radius of the core of the Sun is below 200,000 km.

Front 62

The convection zone of the Sun is from _____ km to _____ km.

Back 62

The convection zone of the Sun is from 500,000 km to 696,000 km.

Front 63

The photosphere of the Sun is _____ km.

Back 63

The photosphere of the Sun is 696,000 km.

Front 64

The radiation zone of the Sun is from _____ km to _____ km.

Back 64

The radiation zone of the sun is from 200,000 km to 500,000 km.

Front 65

The core has a temperature of _____ K, and it is where _________________.

Back 65

The core has a temperature of 15 million K, and it is where energy is produced (fusion).

Front 66

The radiation zone has temperature of _____ K, and it is where __________ by radiation.

Back 66

The radiation zone has temperature of 7 million K, and it is where energy is transported by radiation.

Front 67

The convection zone has a temperature of _____ K, and it is where __________ by convection.

Back 67

The convection zone has a temperature of 2 million K, and it is where energy is transported by convection.

Front 68

The transportation of energy by convection can be compared to

Back 68

that of boiling water in a pot.

Front 69

The photosphere has a temperature of _____ K and it is where __________.

Back 69

The photosphere has a temperature of 5800 K and it is where the Sun becomes transparent.

Front 70

The photosphere is also referred to as the _____.

Back 70

The photosphere is also referred to as the surface.

Front 71

We can construct __________ to describe the state of solar material from _____ to _____.

Back 71

We can construct computer models to describe state of solar material from core to atmosphere.

Front 72

Describe helioseismology (test 1) used to verify the solar model.

Back 72

Sun vibrates (rings like a bell), and it uses waves to test interior structure; same principle as geologists/geophysicists with earthquakes.

Front 73

How do astronomers probe the solar interior?

Back 73

Astronomers probe the solar interior using the Sun's own vibrations.

Front 74

What are the two tests used to verify the solar model?

Back 74

Test 1: helioseismology and test 2: the neutrino trap

Front 75

What are nuetrinos?

Back 75

Nuetrinos are byproducts of fusion, and unlike photos, nuetrinos escape solar interior very easily. The particles are 'ghost-like' very hard to detect.

Front 76

How many neutrinos go through earth?

Back 76

10**14 solar neutrinos per second go through 1 cubic meter on earth.

Front 77

Describe a neutrino trap.

Back 77

A neutrino trap is a tank filled with 100,000 gal of common cleaning fluid, tetrachloroethylene. It was located in a rock cavity 4,850 feet below the surface in the Homestake Mine in the town of Lead, SD.

Front 78

Who ran the neutrino trap experiment?

Back 78

Raymond Davis Jr. of Brookhaven National Laboratory for over 30 years.

Front 79

What was problematic in the neutrino trap experiment?

Back 79

The discrepancy between the Sun's output of expected neutrinos and the actual measure neutrinos.

Front 80

How was the problem in the neutrino trap experiment resolved?

Back 80

The new understanding of neutrino physics and the discovery of three types of neutrinos resolved the discrepancy of the number of expected neutrinos produced by the Sun's interior. Two-thirds of the neutrinos from the Sun changes into two types which could not be caught by the detectors in use in the experiment.

Front 81

Why can you not see the Sun's core?

Back 81

The core of the Sun is hidden because gases become opaque.

Front 82

What is remarkable about the outermost layers of the Sun?

Back 82

Outermost layers of the Sun show remarkable structures, i.e. "atmosphere."

Front 83

The Sun's atmosphere (outermost layers of the Sun) are large/tiny and much more/less dense than the interior. (Circle one)

Back 83

The Sun's atmosphere (outermost layers of the Sun) are tiny and much less dense than the interior.

Front 84

What is the most important part of the sun for our life on Earth?

Back 84

The solar atmosphere is the most imporatnt for life on Earth.

Front 85

Where does almost all of the visible light from the Sun emanate from?

Back 85

Almost all the visible light from the Sun emanate from the photosphere.

Front 86

The photosphere is a small/large layer of gas. (Circle one)

Back 86

The photosphere is a small layer of gas.

Front 87

Temperature decreases/increases upwards in the photosphere. (Circle one)

Back 87

Temperature decreases upwards in photosphere.

Front 88

Sun looks darker/lighter at the edge at the photosphere because it is higher and hence hotter/cooler. (Circle one)

Back 88

Sun looks darker at the edge at the photosphere because it is higher and hence cooler.

Front 89

The further out you are in the photosphere, the hotter/cooler the layers are.

Back 89

The further out you are in the photosphere, the cooler the layers are.

Front 90

The "cool" gas in the photosphere at the upper edge of the atmosphere is _____ K.

Back 90

The "cool" gas in the photosphere at the upper edge of the atmosphere is 4400 K.

Front 91

Solar granulation is

Back 91

Solar granulation is convection cells of gas in photosphere.

Front 92

How many granules cover the solar surface?

Back 92

4 million granules

Front 93

Each solar granules cover area about the size of two U.S. states combined. Which ones are they?

Back 93

Each solar granules covers area about the size of Texas and Oklahoma combined.

Front 94

Describe the process of convection.

Back 94

Hot blob rises; cooler water sinks, or in the photosphere, hotter gas rises and cooler gas sinks in the .

Front 95

Many of the solar granules expand/contract rapidly at the end/beginning of their lives.

Back 95

Many of the solar granules expand outward rapidly (measurable by 2-minute increments) at the end of their lives.

Front 96

Above the photosphere is the ______.

Back 96

Above the photosphere is the chromosphere. A

Front 97

The chromosphere is less/more dense and hotter/colder temperature than the photosphere. (Circle one)

Back 97

The chromosphere is less dense and hotter than the chromosphere.

Front 98

What extends upwards from the photosphere into the chromosphere?

Back 98

Spicules extend upwards from the photosphere into the chromosphere.

Front 99

The top of the chromosphere is _____ K.

Back 99

The top of the chromosphere is 25,000 K.

Front 100

Approximately _____ spicules exist at one time in the chromosphere, each spicule lasting about _____ minutes.

Back 100

Approxmiately 300,000 spicules exist at one time, each spicule lasting about 15 minutes

Front 101

The solar chromosphere covers about ~___% of the solar surface.

Back 101

The solar chromosphere covers about ~1% of the solar surface.

Front 102

The solar chromosphere is a phenomenon related to the Sun's _____.

Back 102

The solar chromosphere is a phenomenon related to the Sun's magnetic field.

Front 103

List all the parts of the Sun's atmosphere:

Back 103

photosphere, chromosphere, corona

Front 104

The outermost layer of the solar atmosphere is

Back 104

The corona.

Front 105

The corona is made of very high/low temperature gases at extremely low/high density. (Circle one)

Back 105

The corona is made of very high temperature gases at extremely low density

Front 106

What happens in the solar corona?

Back 106

The solar corona blends into the
solar wind at great distances from the Sun

Front 107

The temperature rises/falls by about a factor of _____ in the narrow transition region between the chromosphere and the corona.

Back 107

The temperature rises by about a factor of 100 in the narrow transition region between the chromosphere and the corona.

Front 108

A comet went into the Sun on Saturdy morning, April 10, 2010. Did it come out?

Back 108

Hell naw.

Front 109

Activities in the corona includes

Back 109

coronal mass ejections and coronal holes.

Front 110

What lies on top of sunspot groups in the corona?

Back 110

Bright areas lie on top of sunspot groups.

Front 111

What is a prominence?

Back 111

A prominence is a large, bright, gaseous feature extending outward from the Sun's surface.

Front 112

What is the umbra?

Back 112

The umbra is the inner, dark, "cool" region of a sun spot.

Front 113

The temperature of the sunspots is about _____ K. The temperature surrounding the sunspots are about _____ K.

Back 113

The sunspots are 4,500 K. The temperature surrounding the sunspots are about 5,800 K.

Front 114

What do magnetic fields of sunspots do?

Back 114

Magnetic fields of sunspots suppress convection and prevent surrounding plasma from sliding sideways into sunspots.

Front 115

What is the Maunder minimum?

Back 115

The period when sunspots became exceedingly rare, as noted by solar observers of the time (1645-1715).

Front 116

Do the number of sunspots fluctuate?

Back 116

Yes, and they have cycles to it.

Front 117

Solar Cycle 24 is shaping up to be the weakest/strongest solar cycle in more than 50 years.

Back 117

Solar Cycle 24 is shaping up to be the weakest solar cycle in more than 50 years.

Front 118

Weak solar cycles have been known to produce very weak/strong flares.

Back 118

Weak solar cycles have been known to produce very strong flares.

Front 119

The strongest solar storm in recorded history is _______, and occurred during a relatively weak solar cycle.

Back 119

The strongest solar storm in recorded history is the Carrington Event of 1859, and occurred during a relatively weak solar cycle.

Front 120

We are progressing towards Solar Max/Min. (Pick one)

Back 120

We are progressing towards Solar Max.

Front 121

The variation in luminosity over the 11 year solar cycle amount to only ____% of the Sun's total output.

Back 121

The variation in luminosity over the 11 year solar cycle amount to only 1/10% of the Sun's total output.

Front 122

Even typical short term variations in luminosity of the Sun of _____% in incident irradiance exceed all other energy sources (such as natural radioactivity in Earth's core) combined.

Back 122

Even typical short term variations in luminosity of the Sun of 0.1% in incident irradiance exceed all other energy sources (such as natural radioactivity in Earth's core) combined.

Front 123

What radiation peaks during the years around solar maximum?

Back 123

The Sun's extreme ultraviolet (EUV) radiation peaks during the years around solar maximum.

Front 124

The sun's output varies by factors of ___ or more within the relatively narrow band of ______ wavelengths.

Back 124

The sun's output varies by factors of 10 or more within the relatively narrow band of EUV wavelengths

Front 125

What happens to the Earth's atmosphere with extreme EUV variance during the years around the solar maximum?

Back 125

The extreme EUV variance during the years around the solar maximum strongly affects the chemistry and thermal structure of the upper atmosphere of the Earth.

Front 126

Outside the sunspot, the magnetic field is weak/strong and the iron absorption line is single/splits into three. (Pick one)

Back 126

Outside the sunspot, the magnetic field is weak and the iron absorption line is single.

Front 127

Within the sunspot, the magnetic field is weak/strong and the iron absorption line is single/splits into three. (Pick one)

Back 127

Within the sunspot, the magnetic field is strong and the iron absorption line is splits into three.

Front 128

What are post flare loops?

Back 128

Often seen after the hours following a solar flare, post flare loops are a series of loops above the surface of the Sun.

Front 129

What is a solar flare?

Back 129

A brief eruption of intense high-energy radiation from the sun's surface.

Front 130

What are coronal mass ejections (CME)?

Back 130

A coronal mass ejection (CME) is a massive burst of solar wind and magnetic fields rising above the solar corona or being released into space.

Front 131

What are coronal holes?

Back 131

Coronal holes are areas where the Sun's corona is darker, and colder, and has lower-density plasma than average.

Front 132

Why are post flare loops cooler than the corona?

Back 132

The post flare loops are confined magnetically, and the material is somewhat isolated from the million degree corona and can cool to much lower temperatures.

Front 133

Coronal mass ejections are most notably associated with

Back 133

solar flares, but a causal relationship has not been established.

Front 134

How does a post loop flare form?

Back 134

Material "condenses" out of the Sun's hot corona in tops of these loops and then flows down the legs of the loops onto the surface.

Front 135

What is a solar flare associated with?

Back 135

Solar flares are associated with sunspots.

Front 136

What disturbances on Earth can sunspots cause?

Back 136

Sunspot causes electromagnetic disturbances on the earth, as with radio frequency communications and power line transmissions.

Front 137

What is the penumbra?

Back 137

The penumbra is the outer, relatively light region of a sun spot. It is shaped like a ring surrounding the darker, cooler umbra.

Front 138

The penumbra is cooler/hotter than the umbra.

Back 138

The penumbra is hotter than the umbra.

Front 139

The umbra is cooler/hotter than the penumbra.

Back 139

The penumbra is cooler than the umbra.

Front 140

How hot (or "cool") is the umbra?

Back 140

3700 K

Front 141

The Sun's magnetic field is very strong/weak in the umbra.

Back 141

The Sun's magnetic field is very strong in the umbra.

Front 142

A prominence is anchored to the Sun's surface in the _____, and extend outwards into the Sun's _____.

Back 142

A prominence is anchored to the Sun's surface in the photosphere, and extend outwards into the Sun's corona.