Final Exam Astronomy

Front 1

Source of the Sun's heat

Back 1

The sun's heat is the result of thermonuclear reactions at its core. It does so by converting hydrogen into helium through a process called hydrogen fusion.

Front 2

luminosity

Back 2

the total amount of energy emitted by the sun

Front 3

Process of hydrogen fusion

Back 3

called the proton-proton chain.
step 1: a) two protons (hydrogen nuclei 1H) collide
b) one of the protons changes into a neutron the proton and neutron form a hydrogen isotope (2H)
c) One byproduct of converting a proton to a neutron is a neutral, nearly massless (v). This escapes from the sun
d) the other byproduct of converting a proton to a neutron is a positively charged electron, or positron (e+) This encounters an ordinary electron, annihilating both particles and converting them into gamma ray photons. the energy of thes photons goes into sustaining the sun's internal heat.
Step 2: a) the 2H nucleus produced in step 1 collides with a third proton (1H)
b) the result of the collision is a helium isotope (3He) with two protons and 1 neutron.
c) this nuclear reaction releases another gamma ray photon. its energy also goes into sustaining the internal heat of the Sun.
Step 3) a0 the 3He nucleus produced in step 2 collides with another 3He nucleus produced from three other protons.
b) two protons and two neutrons from the two he nuclei rearrange themselves into a different helium isotope 4He.
c)the two remaining protons are released. the energy of their motion contributes to the sun;s internal heat.
d) six 1H nuclei wnet into producing the two 3He nuclei which combine to make 4He nucleus. since two of the oribinal 1H nuclei are returned to their original state, we can summerize the three steps as 4 1H----->4He+ energy

Front 4

Hydrostatic Equilibrium

Back 4

The sun will move neither up nor down.
1. the downward pressure of the layers of solar material above the slab.
2. The upward pressure of the hot gases beneath the slab.
3. the slab's weight-that is, the downward gravitational pull it feels from the rest of the sun.

The pressure from below must balance both the slab's weight and the pressure from above.

Front 5

Thermal Equilbrium

Back 5

While the temperature in the solar interior is different at different levels, the temperature at each depth remains constant in time.

Front 6

Hydrostatic Equilibrium

Back 6

The sun will move neither up nor down.
1. the downward pressure of the layers of solar material above the slab.
2. The upward pressure of the hot gases beneath the slab.
3. the slab's weight-that is, the downward gravitational pull it feels from the rest of the sun.

The pressure from below must balance both the slab's weight and the pressure from above.

Front 7

Three Methods of Energy Transport from the center to the surface

Back 7

Conduction, Convention, Radiative Diffusion

Front 8

Conduction

Back 8

Example: If you heat one end of a metal bar, energy flows to the other end of the bar and makes that warm

Front 9

Thermal Equilbrium

Back 9

While the temperature in the solar interior is different at different levels, the temperature at each depth remains constant in time.

Front 10

Convection

Back 10

Circulation of fluids: gasses or liquids- between hot and cool regions. Hot gasses rise toward a stars surface, and cool gasses sink to the bottom

Front 11

Three Methods of Energy Transport from the center to the surface

Back 11

Conduction, Convention, Radiative Diffusion

Front 12

Conduction

Back 12

Example: If you heat one end of a metal bar, energy flows to the other end of the bar and makes that warm

Front 13

Convection

Back 13

Circulation of fluids: gasses or liquids- between hot and cool regions. Hot gasses rise toward a stars surface, and cool gasses sink to the bottom

Front 14

Radiative Diffusion

Back 14

Photons created in the thermonuclear inferno of the star's center diffuse towards the star's surface.

Front 15

From the center of the sun to about .71 Rsun

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Energy is transported by radiative diffusion. Called the Radiative Zone

Front 16

Beyond .71Rsun

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Convection dominates, called convective zone.

Front 17

field of solarresearch

Back 17

helioseismology

Front 18

Neutrino

Back 18

particles released in the process of hydrogen fusion when protons turn to neutrons. They have no electrical charge. They interact weakly with matter.

Front 19

Photosphere:

Back 19

his is the layer that is closest to the solar interior. This layer forms the
visible boundary of the Sun. Its temperatures range from about 5800 K near the interior edge
down to about 4000 K at the chromosphere boundary. Granulation (the visible manifestation of
convection) and sunspots occur in the photosphere. Absorption line spectra are seen from this
region of the Sun’s atmosphere.

Front 20

Chromosphere:

Back 20

Next layer of the Sun’s atmosphere moving outward from the Sun’s interior.
The chromosphere lies in between the photosphere and the transition region. Temperatures
here vary from 4000 K up to about 10,000 K. Spicules are produced in this region, as are some
absorption and some emission line spectra. Emission from Hydrogen Balmer series lines dominates
the spectrum of the chromosphere. The red Hα line when seen in emission gives the chromosphere
its pinkish red color.

Front 21

Transition region:

Back 21

A region characterized by a rapid increase in temperature over a very
small change in distance. Here the temps go from about 10,000 K up to nearly a million K over a
distance of some 20 km. This part of the solar atmosphere lies in between the chromosphere and
the corona.

Front 22

Corona:

Back 22

This is the outermost layer of the solar atmosphere. This layer has temps of 1 to 2
million K and it also has a very low density. The corona displays such features as coronal holes,
prominences, and coronal mass ejections. The millions of tons of charged particles that escape
from the Sun’s gravitational grasp each year come from the Sun’s corona – this is the source of
the solar wind.

Front 23

small angle formula

Back 23

D=ad/202,265 where D=linear size of an object, d=distance of the object, a=the angular size of the object

Front 24

ecliptic

Back 24

the circular path that the sun appears to trace out against the background of the stars

Front 25

Equinox

Back 25

the point where the celestial equator and the ecliptic intersect

Front 26

Winter solstice

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the point when the sun is furthest south of the celestial equator

Front 27

Summer solstice

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the point when the sun is furthest north of the celestial equator

Front 28

Right acension

Back 28

the angular distance of an object eastward from the vernal equinox along the celestial equator

Front 29

declination

Back 29

an object's angular distance north or south lf the celestial equator measured along a circle passing through both celestial poles.

Front 30

meridian

Back 30

the line that passes through a zenith

Front 31

1-to-1 spin-orbit coupling

Back 31

synchronous rotation, rotation period equals period of revolution

Front 32

3-to-2 spin orbit coupling

Back 32

Mercury's cycle. It makes three complete rotations on its axisfor two complete orbits around the sun.

Front 33

retrograde rotation

Back 33

planet rotates on its axis opposite as compared to how it rotates the sun. Venus does this

Front 34

Greenhouse Effects

Back 34

Our atmosphere prevents some of the radiation emitted by the earth's surface from escaping into space.
1. Sunlight arrives at earth.
2. 39% of sunlight is reflected by clouds and the surface.
3. sunlight is not relfected is absorbed by surface heating it
4. heated surface emits infated radiation
5. some infrared ratiation is trapped by atsmosphere heating both the atsmposphere and surface.
6. remaining infrared radiation "leaks" into space.

Front 35

Greenhouse Gasses

Back 35

certain gasses in our atsmosphere, such as water vapor and carbon dioxide, which are transparent to visible light but not to infared radiation.

Front 36

core

Back 36

central, composed or irron

Front 37

mantle

Back 37

dense rich minerals aroun the core

Front 38

crust

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light silicon-rich minerals on the outside

Front 39

earthquakes

Back 39

stresses build up in the earth's crust and are released. most occur deep in the crust.

Front 40

epicenter

Back 40

area above where the earthquake happened

Front 41

seismographs

Back 41

they detect earth to detect and record these vibratory motions.

Front 42

Earth's energy source

Back 42

mostly from the sun. the earth's surface is warmed by sunlight which in turn warms the air next to the surface. Hot air is less dense than cool air and so tends to rise. the rising air cools and becomes denser. It is called convection.

Front 43

albedo

Back 43

the fraction of sunlight the incoming sunlight. About 31% of it

Front 44

seismic waves

Back 44

three types of waves produced by earthquake

Front 45

surface waves

Back 45

causes the rolling motion that we feel around the epicenter

Front 46

P waves

Back 46

primary waves. Longitudinal waves because they travel pararlell to the direction of wave motion.

Front 47

S waves

Back 47

secondary waves. called transverse waves because their vibrations are perpinicular to the directions in which waves move.