Method of solving any problem in our lives, in society, government, etc., first use of the internet to share data dealing with Particle Physics.

Transcription

1 ASTRONOMY 100 STUDY GUIDE and COURSE CONTENT (Revised Spring 2013) Recommended Text: Any introductory Astronomy textbook that has less than a 5 year copyright date. Required Lecture Notes: Palomar College Astronomy 100 Lecture Notes, J. Pesavento, 2013 (Located at Off Campus Books) I. Scientific Method CONCEPTS: We try to understand and explain the Universe and its activities. We can be deceived in our observations. A. Three steps of the Scientific Method 1. Observation, Theory and Test 2. Facts can change due to lack of proper observations B. Model, theory and fact 1. Using computers to model and/or predict an event of phenomena 2. The relationship between theory and fact C. Communication of ideas 1 APPLICATION: Method of solving any problem in our lives, in society, government, etc., first use of the internet to share data dealing with Particle Physics. : 1. What are the three steps of the Scientific Method? 2. What is the basic problem that we humans have when we observe something? 3. How does computer modeling help in understanding a phenomenon? 4. What is the difference between theory and fact? II. Practical Uses of Astronomy CONCEPTS: There are many things that we use every day to make our lives easier and more productive. There are devices that save lives. Many of these were developed as a result of astronomers trying to understand our universe and our place in it. III. Celestial Sphere CONCEPTS- Using the Earth's orientation in space, i.e., orbital plane, spin axis and equator, we set up references in the sky. We use the references to track the position of objects, like the sun. We discover that the sun has a regular motion which causes seasons. The noon position of the sun in the sky is low or high depending on the time of year. We also find a slow shift of the stars with respect to our references. A. Earth centered (Geocentric) B. Dome of the sky (Celestial Sphere) C. Common references on the sky 1. Zenith and Horizon 2. North Celestial Pole a. Rotation of the Earth (Foucault Pendulum) a. How to find your latitude b. North, East, South & West (Cardinal points) on Horizon c. Meridian 3. Celestial Equator

2 2 4. Ecliptic D. Precession and its causes E. Tilt of Earth's axis 1. Concentration of solar energy 2. Cause of Seasons (Equinoxes and Solstices) APPLICATION: Navigation, location on planet, maps, growing crops, water storage and conservation, global warming, glacial periods What is the Zenith and how does the definition of the Horizon relate to it? 2. What is the relationship between the north pole of the Earth and the North Celestial Pole? 2.5 How did we prove that the Earth is rotating and not the sky? 3. Does the North Celestial Pole remain in the same place in the sky for everyone on the Earth at a particular time? How can you find your latitude by observing the North Celestial Pole? 4. What is the Meridian, what reference points in the sky does it go through and what is its purpose? 5. How does the Equator of the Earth relate to the Celestial Equator? 6. What are two definitions of the Ecliptic and how do we use it in relationship to other objects in our Solar System? 7. What is a Gyroscope? What property does the spin axis have when the mass is rotating? 8. If the gyroscope is placed on the Earth, what happens to its spin axis as the mass rotates? 9. What is Precession? 10. What are the two conditions of the Earth and its Moon that cause precession of the axis of the Earth? Given theses two conditions, how does the Moon s Gravity pull on the Earth? 11. How did Hipparchus discover precession? 12. For a planet to have no seasons what must take place as it orbits the sun? 13. If a planet has seasons, what is the relationship between the spin axis of the planet and its orbital plane? 14. What is the angle between the Ecliptic and the Celestial Equator and what does this have to do with seasons of the Earth? 15. Where is the sun s location in the sky at noon at the Summer Solstice and the Winter Solstice with respect to the Celestial Equator? Where on the horizon with respect to East does the sun rise and set at these two times of the year? Where does the Celestial Equator intersect the Horizon? How does that affect the length of the daylight hours? 16. Why isn t the hottest day of the year on the Summer Solstice and the coldest on the Winter Solstice in the Northern Hemisphere of the Earth? What does this have to do with the incoming and outgoing of energy that originated in the Sun - Solar Energy? 17. Where is the sun located with respect to the Celestial Equator at the two Equinoxes? Where does the sun rise and set at the Equinoxes? 18. Given the latitude and longitude on the Earth, where must you be located to have the sun at the Zenith at the Summer Solstice; and then at Winter Solstice? If you were located on the Equator of the Earth, where would the sun be in the sky at noon, at sunrise and at sunset during the Equinoxes? Why? 19. Why are the seasons just the opposite when you compare the northern and southern hemispheres? 20. What are the Perihelion and Aphelion points of an orbiting object? Why doesn t the Perihelion and Aphelion of the Earth have anything to do with the cause of seasons? Since Perihelion and Aphelion do not cause seasons, how do they modulate the temperatures of the seasons in the northern and southern hemispheres?

3 3 IV. Earth, Moon and Sun Interactions CONCEPTS: Being illuminated by the sun, the moon's position with respect to the Earth causes us to see sections of the moon as it orbits around the Earth. If the sun, moon and Earth are nearly in a straight line, shadows will fall on one of the objects. A. Phases of the Moon-Relationships of names, how much is illuminated & positions B. Moon s orbit around the Earth and what part is illuminated C. Synchronous Orbits and lowest Energy Configuration D. Local Time E. Solar and Lunar Eclipses 1. Nodes 2. Conditions for an eclipse 3. Shadows 4. Path of Totality 5. Lunar Eclipse colors APPLICATION: Understanding of our sun (which provides almost all of our energy), origin of our system and us humans, psychological effects, beauty... : 1. From the Earth, why do we see the Moon going through phases? 2. What are the eight phases of the Moon as seen from the Earth and what are the angles of the Sun, Earth and Moon associated with the phases? 3. Does the moon kept one side facing the Earth as it orbits the Earth and what is this called? Why does this occur for many of the satellites of other planets? What did we realize about the energy configuration of all dynamic systems in our Universe? 4. What is local time and how does it work? Does it change throughout the year? 5. Why don t we have eclipses every new and full Phase of the Moon? 6. What is the importance of knowing the Nodes of an orbiting Body? 7. What are the two conditions to have an eclipse of any type? 8. Why don t we have an eclipse exactly six months apart? 9. There are three shadow regions caused by the Earth or Moon. What are the names of these regions and what can you see of the sun if you were located in each of them? 10. What are the names of the three types of Solar Eclipses and what do they look like from the Earth? 11. What is meant by the path of totality during a Total Solar Eclipse? 12. What are the names of the three types of Lunar Eclipses and what do they look like from the Earth? 13. Explain the two reasons that the Moon turns a red-orange color during a Total Lunar Eclipse. V. Dynamics of the Solar System CONCEPTS: As humans learn more about our Universe, we find that one person makes a discovery, then another person learns about that new information and builds on that making further discoveries. Thus, our understanding improves. Newton would not have been able to formulate gravitational laws without those that went before him. A. Nicholas Copernicus 1. Retrograde Motion a. Use of Epicycles by ancient astronomers due to Geocentric Model b. Heliocentric Model describes planetary motion as seen by the Earth

4 4 c. Found different speeds of planets 2. Sidereal and Synodic Periods B. Tycho Brahe and Johannes Kepler 1. Attempts to determine distances of objects by Parallax 2. Data on positions of planets 3. Kepler s Three Laws of Planetary Motion C. Galileo Galilei 1. Used telescope to observe Sun (Sunspots and rotation), Moon and Planets 2. First proof of Heliocentric model by observing Venus s phases and position 3. Moving objects on/near the surface of the Earth D. Isaac Newton 1. Three Laws of Motion 2. Gravitation as a Force 3. Tides APPLICATION: Too many for even a simple list, but includes: building any structure (engineering), uses of man-made satellites, origins, tidal predictions... : 1. What is Retrograde Motion and how do epicycles work to explain it? Were epicycles meant to describe the reality of the Solar System? What actually causes Retrograde Motion in the Solar System that we now understand? 2. What is the difference between Sidereal and Synodic Periods of the planets? Can you observe both Periods of planets? Which one must be calculated for planets? Why is the Sidereal and the Synodic Periods of our Moon observed and why do they differ in the segment of time? 3. After Copernicus was able to determine the Sidereal Period of the Planets, What property of a planet was he able to calculate that was needed to explain how Retrograde Motion worked? Why? 4. Why is Tycho Brahe considered the best astronomical observer before the invention of telescopes? 5. What is Parallax, how does it work and what piece of information do we obtain from its use? 6. Why couldn t Tycho Brahe accept the idea that the Earth was moving around the Sun? What was his concept of the Solar System? Was this based on the Scientific Method? 7. What are Kepler s three Laws of Planetary Motion? What is an ellipse? What is meant by Eccentricity? What does the second Law tells us about the speed of a planet as it moves around the Sun? How does this relate to Copernicus s discovery of how the speed of the planets depend on their proximity to the Sun? Concerning two orbiting bodies, what does the third law allow us to calculate? How did these laws influence Newton s Law of Gravity? 8. In using the telescope, what did Galileo discover about the Moon? By observing Sunspots from day to day what did he observe the sun to do (not because the Earth was going around it)? At certain times of the years, why did Galileo observe the Sunspots move in a curve instead of a straight line? What was the significance of observing satellites moving around Jupiter with respect to the Heliocentric Theory? How did he prove that Venus must orbit around the Sun (not just its phases)? 9. How did Galileo start to understand friction and inertia? What did he discover about falling objects that helped Newton with Gravity? Contrary to Aristotle, what did Galileo discover about falling objects of two different masses? Does the falling of an object moving horizontally differ from one that has no horizontal component of motion? Why not? 10. Why is it important to specify the reference frame when talking about motion in our Universe? 11. What are the two states or conditions that a mass can have in the universe in dealing with the concept of Inertia? What is the difference between speed and velocity? What is meant by Uniform Velocity? If a car turns a corner, are the occupants forced out of the moving vehicle? Why Not?

5 12. What is Acceleration? How does Force, Mass and Acceleration relate to each other as one increases or decreases? Why do planets orbit around the Sun and not move in a straight line? What is the difference between weight and mass? How do we measure Mass? What is the relationship between mass and inertia? 13. Is it possible to apply a force on a mass and not have an equal force applied in the opposite direction? Why not? 14. According to Newton, how is it possible to have a mass not hit the Earth as the mass falls? What is the connection between a falling mass and orbital motion? 15. How does mass control the Force of Gravity? If you double the mass, how does it affect the Force of Gravity? 16. How does the distance between masses affect the Force of Gravity? If you double the distance, what happens to the Force; and if you half the distance, what happens to the Force? 17. Why do masses like the Sun act as if all the mass is concentrated in the center as a point mass? 18. Does the Sun or Moon dominate the Tides on the Earth? How does the actual cause of Tides explain your answer? 19. Why are there two bulges of water on the Earth, one facing the Moon and the other on the opposite side? What is meant by Differential Gravitational Attraction? Why is the Moon s tidal effect twice that of the Sun s, even though the Sun s Gravitational influence is much greater? 20. What are Spring Tides and Neap Tides? What conditions must exist to have these? VI. Telescopes and Instrumentation ( Most of this topic will not be discussed in class. Use your Lecture Notes.) CONCEPTS: We use pieces of equipment that increase the ability of our senses to observe the Universe around us. Technological advances of these devices continue to change our view of the Universe. A. Image Formation B. Brightness and Resolution C. Three types of Optical Telescopes D. Types of Reflecting Telescopes E. Aberrations of Lenses and Mirrors F. Radio Telescopes G. Spectrographs I. Charge-Coupled Devices (CCD'S) 5 APPLICATION: Improvement of all optical devises using lenses and/or mirrors, e.g., cameras, glasses/contact lenses, microscopes; digital cameras, satellite dishes, identification of substances by spectral analysis What property of telescopes allows us to see distant objects better than our eyes? Does magnification have anything to do with this? Why not? 2. Is the orientation, e.g., upside down; of the image that you see in a telescope the same as you observe it to be without the telescope? Why? 3. What two quantities control the brightness and the resolution of an image? What are the differences between a optical and a radio telescope as far as resolution of an image? 4. What are the differences between a Refracting and a Reflecting Telescope? 5. What is the purpose of the Eyepiece? 6. What is the difference between a Newtonian and Cassegrain Reflecting Telescopes? 7. What is Chromatic and Spherical Aberration? What is Coma?

6 8. What is the benefit of using a lens and a mirror in a telescope? 9. What does a Spectrograph do when it is attached to a telescope? What is the essential component of the device? 10. What is a Charge Coupled Device, CCD, and what are some of its uses? VII. Electromagnetic Radiation CONCEPTS: Except for a few cases, the only method we obtain information about our Universe is by receiving electromagnetic radiation, e.g. light, from objects. The better we understand this form of energy, the better we will understand the universe and us in it. In our effort to understand, we have acquired a large amount of useful devises to make our lives easier. A. Wave nature of light 1. Young s Double Slit Experiment 2. Electric and magnetic fields 3. Problem with waves traveling in space a. Assumption of space media called Ether b. Experiment to find Ether with no results after 25 years B. Particle nature of light 1. Photoelectric Effect 2. Einstein s Explanation using photons 3. Energies of various photons C. The entire Electromagnetic Spectrum 6 APPLICATION: Again, too many for even a simple list, but includes: Photovoltaics-electricity from light, all electronic devices, danger of high intensity of EM radiation and the type of EM radiation What is meant by the Wavelength and Frequency of EM Radiation? Describe wave motion like on the ocean? 2. What is Diffraction? What happens to any energy that can be described as a wave when it passes through a small opening? 3. As waves interact with each other, what is the difference between Constructive Interference and Destructive Interference? With optical or visible radiation, how is this demonstrated on the screen where the radiation is observed? Young s Double Slit Experiment demonstrates what aspect of EM radiation? 4. What are the two fields that make up the energy of this kind of radiation, e.g., Light? What is meant by an Energy Field? Describe the Energy Field of Gravity around the Earth. How does this field relate to the Electric Field that a charged particle has? 5. How do we relate the Electric and Magnetic Fields to a wave type of form? 6. Why did we think that light needed a medium to travel through? What was the result of the experiment to detect a medium, i.e., Ether, in the Universe? What did this suggest to Einstein concerning the wave nature of Light? 7. What is the process of interaction between light and atoms in the Photoelectric Effect? How did this prove the Particle Nature of Light? What happens to the emitted electrons when you increase the intensity of Light? What does this indicate about the Photons? What happens to the emitted electrons when you change the color of the light? What does this indicate about the Mass or Energy of a Photon? How does this relate to the Wavelength or Frequency of the Photon? 8. What are the Domains of the EM Spectrum? What can we state about the energy of each Domain? Is there danger in being exposed to EM Radiation of any Wavelength or does it depend on the

7 7 Intensity? VIII. Radiation Laws CONCEPTS: When Electromagnetic radiation is "released" by an object it goes off in all directions. The energy occupies more volume the further you are from the object, thus it appears less intense. By knowing how much less, we can determine how far we are away from the object. Also, the amount and type of radiation given off by an object can be used to determine some properties of the object, like temperature. You do not have to be on top of the object to do this. A. Propagation of light and how light intensity changes with distance B. Black body radiation 1. How different forms of energy transfer a. Kinetic or Motion Energy b. Electromagnetic Energy c. Conversion of one form into another 2. Equilibrium condition 3. Black body curves and their colors 4. Used to determine temperature by energy output and color APPLICATION: Heat sinks in electronics, light emitting devices, insulation of hot or cold environments, cooling of heat engines (like car engines), solar panels to heat water, measurement of an objects temperature What happens to the intensity of Light from a point source, e.g., a star, as distance of the observer changes? If the distance doubles? Does this work like Newton s Law of Gravity? 2. How can energy be transferred from one object to another if there are in contact with each other? What is this energy called? When a thermometer is placed in air what type of temperature does it record? How does it pickup the energy? 3. How does energy pass through a vacuum when the energy transfer has been restricted to Kinetic before it reaches the vacuum? Can Energy change from one form into another? 4. What are the two general properties of a Black Body Radiator? 5. Why does the Sun or any Star act like a Black Body? Do all Black Bodies appear black to our eyes? 6. What are the three properties of Black Body Curves? How do they relate to the Intrinsic Brightness and Color of a star? How do these properties allow us to determine the Black Body Temperature of a star? Can you determine the approximate Black Body Temperature of a star by noting its Color? What is the Surface Temperature of our Sun? IX. Spectroscopy CONCEPTS: Since the electromagnetic energy given off by an object can tells us much about the object; it is best if we could break down the energy into parts, like separate wavelengths, and look carefully at those. This brings up the question of how does that "stuff" produce that particular type of energy. We find that the atoms that make up matter have a given structure and that each type of atom has a slightly different structure. That structure makes the energy given off by that atom unique. By taking the spectrum of the object we can discover chemical composition, temperature, motion, magnetic fields, etc., about the object, even though it may be light-years away.

8 8 A.Types of Spectra 1. Continuous, Absorption and Emission (depending on condition of energy source) 2. Each element has a unique spectrum or set of lines B. Atomic Structure of the Hydrogen atom (other atoms are similar in general structure) 1. Quantum nature a. Why atoms can only absorb or emit particular amounts of energy/radiation b. Energy levels st c. Ground state (1 energy level) 2. How Hydrogen produces an Absorption Spectrum a. Photo-excitation b. Electron moves up to higher energy levels 3. How Hydrogen produces an Emission Spectrum a. Collisional excitation b. Electron moves down to lower energy levels 4. How hydrogen produces a Continuous Spectrum a. Ionization - Removal of one or more electrons from the atom b. Recapture of an electron by an ionized atom c. Kinetic Energy plus the Transition Energy produces one photon APPLICATION: Again, too many for a simple list, but includes: all electronic devices, all devices that receive or transmit radiation, identification of substances, determining temperatures of any object, all medical uses of EM radiation, e.g., X-rays machines, any radiation therapy; fluorescent lights What are the three Types of Spectra and what do they look like as far as having or not having dark or bright spectral lines? In general, what is the conditions (solid/liquid/gas, hot/cold, high/low density) of the materials that produce/absorb the radiation? 2. What enable us to uniquely determine the Element that is producing or absorbing the EM Radiation in the Spectrum? Does it make any difference in the identification of the element if the spectrum is Absorption or Emission? 3. What is the difference between the orbital structure of a satellite around the Earth and the orbital structure of the electron around the proton of the Hydrogen Atom? Is the electron restricted to particular positions with respect to the proton? What is the relationship between the Energy used or produced by a satellite and the electron? 4. What causes the atom to absorb or emit a particular photon? Does this have to do with the Energy Levels of the atom? What is the relationship between the space between the Energy Levels and the wavelength/energy of the photon that is absorbed or emitted? 5. When a photon is absorbed, does the electron move up or down in its energy structure? Why? 6. If a Hydrogen atom is excited, where is the electron in the energy structure? Is the atom neutral in the excited state? What is meant by a neutral atom? Does this have anything to do with charge? 7. How are the Balmer lines in Absorption related to the electron transitions in the energy levels of the Hydrogen atom? What is the wavelength of the line that we call H-Alpha? What is its corresponding electron energy level jump (what numbers) of H-Alpha? 8. What are two methods of exciting an atom? 9. How does an atom transfer Kinetic Energy into EM Energy? How do florescent lights work? 10. How are the Balmer lines in Emission related to the electron transitions in the energy levels of the Hydrogen atom?

9 11. To produce a Continuous Spectrum, what must be done to the atom? What is this process called? 12. What happens when an atom captures an electron? Can the electron stop an any energy level? What happens to the kinetic energy of the electron when it was captured? How does a tungsten light bulb produce energy? A 150 POINT MID-TERM EXAM WILL NOW BE GIVEN COVERING ALL THE MATERIAL THROUGH TOPIC IX. X. Stellar Observations and Measurements CONCEPTS: Stars are classified by their surface temperature as indicated by their spectrum. The spectral absorption lines contain information about the chemical abundances of elements, magnetic fields, rotation, and a few other properties of stars. We can also determine by the spectrum if the object is moving with respect to us, what direction it is moving and its speed. This is done by noting the shift of the spectral lines from where they normally would be. The brightness of a star is placed on a magnitude scale. If the distance to the star can be found, the intrinsic brightness or absolute magnitude can be calculated. The only direct method of finding the distances to stars is by measuring their parallax. A. Spectra of stars 1. Classification according to surface temperature 2. How to determine the general chemical composition of an object without using spectrum 3. Information from a star s spectrum a. How to tell the surface temperature of the star (1) From lines of elements shown to be present in the star (2) From the state of the atoms, i.e., ionized or not b. Chemical Abundances (1) At a particular temperature are all element seen in the spectrum? (2) Why is hydrogen not seen in O and M stars? (3) At a given temperature, why don t we see particular elements when the conditions indicate that we should? c. Doppler Effect (movement of object) d. How do we tell if the star is Rotating and how fast? e. Magnetic Fields 3. Stellar magnitudes a. apparent magnitude b. absolute magnitude - brightness at 10 parsecs C. Distances to stars - Trigonometric Parallax 1. What are the spectral classes of stars and what property of stars does the classification depend? 2. How does the color of the star change with the spectral class? What is the relationship between the color of the spectral classes and blackbody radiation? 3. If all stars are made up of almost entirely of Hydrogen and Helium, why are the spectra of each class so different? What is meant by Density of a material or object? How can we determine the general chemical composition of a star? What is meant by the average density of an object? How does the average density differ from the uncompressed density? By using uncompressed density how do we arrive at a good guess of the chemical composition of the object? 4. Given the structure of atoms and their ability to absorb and emit energy, what would cause O type stars to have only HeI and HeII lines with no HI lines? What is the state of most of the Hydrogen atoms? 9

10 5. Why do A type stars have very dark Hydrogen absorption lines? 6. Why do M type stars have almost no Hydrogen absorption lines? 7. When we look at relatively cooler stellar surface temperatures, what causes the spectral lines of ionized heavy elements to be present; and those stars that are cooler still, to have the spectrum of neutral heavy elements present? 8. Due to the Doppler Effect, how are the spectral lines shifted if the source and/or the observer is moving toward each other? Why? 9. What about if the source and/or the observer is moving away from each other? Why? 10. How does the spectrum of a fast rotation star differ from one that has slow rotation? Are all of the spectral lines affect by the rotation? 11. How does the presents of a magnetic field affect the spectral lines of a star compared to rotation effects? Are all spectral lines affected by magnetic fields? 12. In summary, what are six properties of stars that can be determined by the careful examination of the spectral lines? 13. How does the numbering system work in dealing with the magnitude or brightness of stars, i.e., do the numbers become larger or smaller when you are measuring brighter stars? 14. What is meant by apparent magnitude and does it depend on the size of the telescope that is used, i.e., does a particular star have a different apparent magnitude in a larger telescope? How do we handle the problem of different sizes of telescopes in determining the Apparent Magnitude? 15. What is the difference between Apparent and Absolute Magnitudes? 16. How do we obtain the absolute magnitude of our sun? How does this relate to changes of brightness with distance? 17. Using drawings and words describe Trigonometric Parallax. 18. How is a Parsec defined? 19. Does Trig Parallax depend on any other distance measurement? 20. Why is the accuracy of distances acquired by Trig Parallax so limited to just a relative small number of stars in our Galaxy? XI. Stellar Populations CONCEPTS: Once the surface temperature and absolute magnitude of a star are found, a correlation of these two quantities is seen in the H-R Diagram. This allows us to set up another classification that gives us more information about the stars, e.g., their size and evolutionary condition. An indirect method of finding the mass of Main Sequence stars can be calculated. The H-R diagram can also be used to find the distance to stars. A. H-R Diagram 1. The relationship between the surface temperature and energy output of a star B. Luminosity classes 1. Main Sequence 2. Red Giants 3. White Dwarfs C. Mass-luminosity relationship of M.S. stars 1. Find the mass of a star using gravity 2. Find the absolute magnitude 3. Establish a relationship between mass and luminosity D. Spectroscopic parallax 1. Spectrum gives star s surface temperature and luminosity class 2. H-R Diagram gives Absolute Magnitude 3. Telescope observation gives Apparent Magnitude 4. Distance is calculated due to knowledge of the two magnitudes 10

11 11 1. Draw the H-R Diagram, labeling the axes and indicate the location of the Main Sequence, Red Giants and White Dwarfs. 2. What do the stars on the Main Sequence have in common? What quantity of Main Sequence star varies to cause them to be spread out from the upper left to the lower right? How does this quantity affect the temperature and energy output of the star? 3. If the Red Giants are just as hot as red Main Sequence stars, why are they so bright? 4. Is there a relationship between the mass of a Main Sequence star and its Absolute Magnitude? Why? 5. Describe how you can determine the distance to a star by using the method called Spectroscopic parallax or by taking the spectrum and Apparent Magnitude of a star and using the H-R Diagram. How does this relate to the brightness of a star changing with distance? XII. Stellar Structure CONCEPTS: For a star to be stable it must maintain equilibrium conditions which can be understood by how gases act under given conditions. Since most of the energy of the star originates from the core, that energy must be transported to the surface. There are processes that change the form of the energy before it is emitted into space. How the star produces energy can be understood in the process of fusion in which lighter elements are formed into heavier elements. This is how the universe is enriched with material other than hydrogen and helium that were produced by the Big Bang. A. Hydrostatic and thermal equilibrium B. 1. Hydrostatic - balance between pressure and gravity 2. Thermal - balance between energy into a region and the energy out of the region C. How a normal gas works - Perfect Gas Laws 1. Relationship between temperature, pressure, density and volume D. Degenerate Gases - Electron and Neutron 1. Conditions needed to produce Electron Degeneracy and Neutron Degeneracy E. Energy transport in stars 1. Conduction, Convention and Radiation F. Energy production in stars - Fusion Reactions 1. Fusion is necessary to produce energy in stars 2. Differences between fusion and fission? a. Radioactivity b. How does a Nuclear Reactor work to produce electrical energy? 3. Proton-Proton Reaction (H into He)- anti-matter and neutrino 4. CNO cycle (H into He) and Carbon as a Catalyst 5. Triple Alpha reaction (He into C) 6. Production of elements up to Iron F. Other fusion processes particularly in Supernovae to make heavier than Iron elements 1. The Big Bang produced only Hydrogen and Helium 2. Stars and Supernovae made all the other elements 1. Hydrostatic Equilibrium is the balance between what two properties of a star? 2. How does pressure relate to Force? 3. Thermal Equilibrium is what kind of balance in a star? 4. What happens to the pressure of a gas, like in a star, if the temperature increases? Why? 5. If you add hot particles to the gas or increase gas density, what happens to the pressure? Why?

12 6. If you increase the volume of the gas without adding more particles, what happens to the pressure and what happens to the temperature? 7. Why does the temperature change with changes of volume? 8. What is the difference between a normal gas and a Degenerate Gas? 9. Describe the properties of an Electron Degenerate Gas in terms of space cubicles. 10. What are the ranges of mass (in Solar Masses) that an object must have in order to obtain Electron Degeneracy? 11. What is the size and density of a White Dwarf which is in Electron Degeneracy? 12. Are the space cubicles of a Neutron Degenerate Gas the same size as those of Electron Degenerate Gas? How do they compare in size? 13. What are the ranges of mass that an object must have in order to obtain Neutron Degeneracy? 14. What is a method of forming neutrons in the core of a star? Is the mass of the neutron the sum of the masses of the particles that make it up? Why not? 15. What is the size and density of a Neutron Star? 16. What are the three energy transport Mechanism and how do they work? 17. Draw the energy transport from the core to the photosphere of our sun. 18. What evidence do we have that our sun uses Convection in the upper layers? What does it look like when you are observing the surface of the Sun? What is it called? 19. Does the sun have enough thermal energy from its gravitational collapse to keep it shining through today? How do we know? 20. What is the difference between fusion and fission? 21. What is radioactive decay and how can we use it to determine ages of things, like rocks? 22. In general, how does a nuclear fueled electric generation plant work? How do we heat the water? Can it explode as an atomic bomb? What do we do with the fuel rods once they are used up? 23. In the process of the fusion of Hydrogen, how many Hydrogen atoms are converted into one Helium? What is the minimum temperature for this reaction to take place? What is this reaction called? 24. What are positrons and how do they produce energy in the core of our sun? 25. What are neutrinos and what do they allows us to measure? Are neutrinos easy to detect? Why or Why not? 26. What is the Triple Alpha reactions? What is the fuel and what element is produced? 27. How are the elements that are heavier than helium produced? Why do stars stop fusing once Iron starts to fuse? How are the heavier that Iron atoms produced? XIII. Star's Outer Layers - The Sun as an Example (This will not be discussed in class) CONCEPTS: Since the sun is so close to us, we can us it as an example of a typical star. We can observe the three layers that make up the outer portion of the star. There are many features in the layers that are controlled by magnetic fields. Sunspots are among these features. The energy output of the sun and its "storms" affect the environment of the earth. A. Photosphere B. Chromosphere C. Corona D. Features and phenomena 1. What are the names of the three outer layers of the sun and how are they arranged from inner to outer? 2. What are the temperature of the Photosphere and the Corona? 3. What layer has the largest change in density and temperature? 4. Under what conditions or using what EM Radiation is needed to view each of the three layer? 12

13 13 5. What are spicules? 6, Describe Solar Wind? What is its makeup? 7. How do we observe Coronal Holes and Coronal Mass Ejections? 8. Describe Sunspots, i.e., sizes, relative temperature, magnetic fields, form, etc. 9. What is meant by the Sunspot Cycle? How does it work? What changes occur? 10. What are Faculae and Plages? What do they look like and how do we observe them? 11. What is the difference between filaments and Prominences? 12. What are Solar Flares and how do they affect the Earth? XIV. Interstellar Material CONCEPTS: The Galaxy that we live in contains stars and large masses of gas and dust called nebulae. This material affects how we see the universe around us. The dust can block the light from stars and glowing gas. The gas can produce various kinds of electromagnetic energy to make its presents known. It is from these regions that stars are made. A. Location of Dust and Gas in our Galaxy B. Dust and gas molecules - molecular clouds 1. Dust obscures and colors star light 2. Radio and Infrared to detect and identify dust grains 3. Gas molecules can be identified by microwave emission C. Gas 1. It is transparent 2. The difference between HI and HII Regions 3. Methods of detecting and identifying gas atoms a. Spectra of stars b. Spectra of HII Regions c. Radio and infrared spectra of HI Regions d. 21 cm Radiation of Hydrogen - Shape of our Galaxy D. Bok Globules 1. What are the two types of Interstellar Material and what is the amount of one compared to the other? 2. Describe the dust grains, i.e., their size, state and makeup. 3. What are molecular clouds and how do we identify the molecules they contain? 4. What effect does the dust have on the brightness of stars? Does this effect our measurement of stellar distances? How? 5. How is most of the interstellar gas and dust distributed in our Galaxy? 6. What is the difference between HI and HII Regions? 7. What are the two methods we can use to observe HI Regions? Explain each one. 8. What happens to the electron of the Hydrogen atom in the ground state to absorb and produce energy? 9. What instrument is used to observe the HI Regions? Why? 10. How did we determine that we live in a Spiral Galaxy? 11. What are Bok Globules and what do they have to do with stellar formation? XV. Birth and Evolution to Main Sequence of a One Solar Mass Star CONCEPTS- Gravity plays the key roll in the formation of a star by causing the gas and dust to collapse. As the object collapses the temperature increases until it starts to fuse Hydrogen into Helium. The star remains on the Main Sequence for most of its existence. The temperature of the core increases causing the rest of the star to expand

14 into a red giant. After going through "helium flash", the star changes fuel to helium fusing into carbon. This takes place on the "Horizontal Branch". After this phase the star expands again to be a red giant. The outer layers are removed as a planetary nebula and the remnant object is a white dwarf. A. Formation from Nebulae 1. Gravitational collapse when the condition of HI Region is right 2. Triggering mechanisms - Supernovae, Colliding Galaxies and Density Waves B. Protostar 1. Decrease in size causes increase in temperature 2. Evolutionary tracts on H-R Diagram 3. Early red giant phase 4. Early Solar System 5. Initiation of fusion in core - T Tauri phase C. Zero age main sequence star - H fusion Phase 14 XVI. Evolution beyond Main Sequence of a One Solar Mass Star A. H is used up and He builds in core B. Core contracts - outer portions expand C.What happens to the planets? D. Star becomes a red giant with a degenerate core of helium E. Helium flash F. Star moves onto horizontal branch - helium to carbon fusion G. Planetary nebula phase where envelope is lifted off H. End up as white dwarf in an electron degenerate state 1. In general, what causes stars to form out of nebulae? 2. What are the three triggering mechanism to start the collapse? Explain how these work. Which one is dominant in our Galaxy? Why? 3. Where does the rotational energy of the Solar Nebula originate? 4. How can we observe a Protostar before it produces visible radiation? 5. When we can see it visually what type of an object is it and how can we tell the difference between it and an old evolved star? 6. What is happening to the Protostar when it goes into the T Tauri Phase? What happens to the inner planets at this time? What happens to the mass of the Protostar? 7. When the sun arrived on the Main Sequence was it the same size it is now? Why? 8. Does the temperature of the photoshpere remain the same as the sun goes through the Main Sequence Phase? Why? What does this have to do with the temperature of the Core? 9. Why does the temperature of the Sun s Core increase? Where does the Helium go once it is created by the fusion reactions? Why is the Core smaller? What happens to the distribution of the mass inside the sun? 10. What is happening to the state of the Helium in the Core as the sun leaves the Main Sequence? How does this affect the rest of the star? How quickly does this occur considering the time that the sun remained on the Main Sequence? 11. Does the sun lose mass as it evolves into a Red Giant? How does this affect the orbits of the planets? 12. What will happen to the Earth in about 2 to 3 billion years? 13. What is Helium Flash? What causes it? What happens to the Core? How does the rest of the star

15 15 respond to this change? 14. What happens to the Core after Helium Flash? What is being fused? Does this fusion last a long time compared to the Main Sequence? 15. After the Helium is used up, what is the state of the Core? What happens to the star again? 16. When it is a Red Giant how much of the star s mass is in the Carbon Core? 17. As the temperature of the core increases, what happens to the other 10% of the mass? When this activity takes place, what is the object called and what is in the middle of the object? XVII. Variable Stars CONCEPTS: Certain stars on the horizontal branch vary in light intensity at regular intervals. These stars can be used to determine distances because their absolute magnitude is known. Cepheid variables are used to determine distances to galaxies. If two stars are very close to each other, material can move from one star to another. A. Pulsating variables on horizontal branch 1. RR Lyrae variables - distance indicator a. Harlow Shapley s assumption about our Galaxy b. Distances to Globular Clusters c. Our location in the Galaxy 2. Cepheid Variables - distance indicator a. Period-Luminosity Relationship discovered by Henrietta Leavitt b. Used by Edwin Hubble to find distance to Andromeda Galaxy B. Eruptive variables - sharing of material between stars 1. Novae 1. What are stars doing to produce energy when they are on the Horizontal Branch in the H-R Diagram? 2. What is meant by a star that is a Pulsating Variable? 3. What enables us to determine the distance to RR Lyrae Variables? What property of the star is the same for all of these Variables? 4. How do we recognize a RR Lyrae Variable? How does it change in light intensity? 5. What assumption did Harlow Shapley make about the Location of Globular Clusters as part of our Galaxy? 6. What are Gobular Clusters? What shape do they have and how old are the stars? 7. How did Harlow Shapley determine the distance to the Globular Clusters? 8. If the sun was located in the center of the Galaxy, how would the Clusters be distributed around us? What did Shapley actually find in the distribution of the Clusters and how did that indicate where we are located in the Galaxy? 9. Cepheid Variables are identified by what properties? What type of star are they to be seen over great distances and what is the range of time that they vary in light intensity? 10. How did Henrietta Leavitt determine the relationship between Cepheid Variables period of light change and their luminosity or energy output? What did the distance of the Small Magellanic Cloud have to do with it? 11. What did Edwin Hubble measure with the use of Cepheid Variables. How did this change our view of the Universe? XVIII. Evolution of Massive Stars CONCEPTS: Stars that are more massive than our sun evolve much faster because of the higher temperature in the core. They also have the ability to produce elements that are heavier than Helium by fusion. The very massive stars will become very unstable and explode leaving a

16 neutron star as a remnant. The material that is blown away is rich in heavy elements due to the fusion during the high temperatures of the supernova. A. Relatively fast evolution B. Fusion of carbon, etc., up to iron C. Complex core 1. Production of neutrinos 2. Formation of neutron degenerate core D. Supernova explosion (Type II) 1. Production of heavier than iron elements 2. Neutron Degenerate core a. Violent removal of outer layers of star b. Discovery of Pulsars (1) Light Beacon Theory - magnetic field of star produces synchrotron radiation c. Proof of Neutron Stars - slowing of rotation E. Black Hole formation 1. Relatively how long does a star that is more massive than our Sun remain on the Main Sequence? 2. What happens to the core of these massive stars when Iron starts to fuse? 3. What happens to the outer layers once the core become neutron degenerate? How does this occur? 4. Do all Neutron Star pulsate? Why not? 5. Explain the mechanism that Neutron Star use to produce EM radiation that is called the Light Beacon Theory? 6. How did we test the Light Beacon Theory? 7. What proof do we have that Pulsars are Neutron Stars? XIX. Laws of Relativity CONCEPTS: Before 1900, there emerged some basic problems with light and gravity, i.e., that the speed of light was always the same no matter how you were moving and that Newton's law of gravity could not explain Mercury's orbit. Albert Einstein explained these problems by his Special and General Laws of Relativity. These laws have been tested to the point that we accept them as fact, and we use them to explain other phenomena. A. Special law of Relativity 1. Speed of light - same to all observers 2. Physical laws are the same everywhere 3. Motion effects on observer s measurement of length, mass and time due to changes of Spacetime B. Problem with Newton's Law of Gravity - orbit of Mercury C. Principle of Equivalence D. General Law of Relativity 1. What are Warps in Spacetime? 2. Mass controls the warp of spacetime 3. Spacetime controls how mass and energy move E. Proof and effects of the Law 1. Mercury's orbit 2. Path of light 3. Time 4. Gravitational lenses 16

17 1. What is the difference between the Special and the General Laws of Relativity? 2. What are the two premises of the Special Law? 3. Since we always measure C no matter how we move, what happens to length, mass and time of a moving object as observed by someone outside of the motion? 4. What is the Principle of Equivalence with respect to gravitational fields and acceleration fields? 5. What is meant by a warp in spacetime in terms of mass and the geometry of spacetime? 6. In a simple description of the General Law, how does mass and spacetime interact with each other? 7. What happens to the curvature of spacetime when the object decreases in size without changing mass? 8. At what condition of the curvature is a Black Hole created? 9. What was the first proof of the General Law of Relativity using our Solar System? 10. How did we prove that light does bend around the sun? 11. How did we prove that time is different at two location in a warp? 12. What is a gravitational lens? 17 XX. Black Holes CONCEPTS: If the collapsing mass is greater than 3 solar masses, nothing will stop the collapse. The object will shrink to nothing but will still have mass. No electromagnetic radiation can leave the object. All you can know about the object is its mass, rotation and charge. You can speculate about what happens if you enter a black hole, but you can never prove it. However, you can prove the existence of a black hole by observing how it interacts with matter around it, and that material is still in our Universe for us to observe. A. Gravitational collapse of a massive star B. Singularity C. Event horizon D. Existence through observations - small size and large mass 1. Massive Black Holes in the center of galaxies 2. Classic Black Holes from evolution of massive stars 1. What is the mass limit for a collapsing object to be a Black Hole? 2. What happens to the exit cone as an object collapses into a Black Hole? 3. What is the Event Horizon and the Singularity of a Black Hole? 4. In the discovery of a galactic center Black Hole, what properties must be measured and how do we measure them? 5. What is the relative mass of galactic center Black Holes compared to Black Holes that form from the collapse of a star? 6. What are the observable properties of Black Hole activity that formed from the collapse of a star? XXI. Star Clusters CONCEPTS: We have identified two types of groups of stars in our Galaxy. They both have very distinct properties. They are used to determine the evolution of stars, relative ages of stars, star formation, distances to stars, etc. A. Open or Galactic Clusters B. Globular Clusters

18 18 1. What are the differences between Open or Galactic Clusters and Globular Clusters in terms of number of stars, shape, location in Galaxy, chemical abundances and age? XXII. The Galaxy - "Milky Way" CONCEPTS: Our Galaxy is a spiral system of about 100 billion stars. It is relatively flat in one dimension. We have determined its shape by radio radiation. The stars, gas and dust move around the nucleus of the Galaxy according to gravitational laws. The halo of our Galaxy is a spherical area around the center in which globular cluster are located. A. Size and shape B. Location of sun C. Movement of stars D. 21cm data from hydrogen gas and the spiral structure 1. What is the shape and what are the dimensions (size) of our Galaxy? 2. Where is the Sun located in the Galaxy? XXIII. Galaxies CONCEPTS: Edwin Hubble determined the distances of other galaxies by using Cepheid Variables and other means. He found a relationship between the red shift of the galaxy and its distance. He established "Hubble's Law" of the expanding universe. As we discovered more galaxies we started to classify the different types. Also, we found a distinct distribution of stars in spiral galaxies. A. Curtis-Shapley Debate B. Hubble's Discovery of Cepheid Variables in the Andromeda Galaxy (M31) C. Distance determination and Hubble s Law D. Classification E. Formation F. Galactic Evolution 1. Seyfert Galaxies 2. Quasars 1. What was the basic problem with our view of the Universe in 1920? What was the topic of the Curtis-Shapley Debate? How did Edwin Hubble resolve the problem? 2. What are some of the objects or relationships of observed properties to determine the distance to Galaxies? 3. What was the relationship, known as Hubble s Law, that Hubble discovered by taking spectrum and calculating distances to Galaxies? 4. What are the four types of Galaxies and what do they look like? 5. What is the simple process that we assume took place to form Galaxies? Does this explain the differences in shape, the massive black hole in the center, the spiral structure, etc.? 6. What are Quasars and how were they discovered? 7. What are Seyfert Galaxies and what do they look like? 8. Is there a relationship between Quasars, Seyfert Galaxies and regular Galaxies? XXIV. Cosmology CONCEPTS: Has the universe always been in existence (Steady State Theory) or did it have a beginning