Your First Quiz!

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YOUR FIRST QUIZ!

A quiz on the first day? Yes. But this quiz doesn't count for anything. It's just for fun!

There are twelve questions. Each is "true" or "false." Here they are--in no particular order . . .

1. There are other worlds revolving around other stars, just as our Earth revolves around the Sun.

2. The positions of the planets in the zodiac (Aries, Leo, Aquarius, etc.), at the time of your birth, have an effect on your personality.

3. The build up of so-called greenhouse gases can make a planet so hot as to become uninhabitable.

4. The absence of ozone in an atmosphere makes life below difficult.

5. The only known crash of a flying saucer occurred at Roswell, New Mexico, in 1948.

6. Huge bodies, called asteroids, have smashed down upon the Earth and caused catastrophic destruction.

7. More people become insane during the Full Moon than at any other time.

8. It would take days, weeks, or even months to travel among the stars.

9. Astronomers search for extraterrestrial life (ET).

10. Columbus discovered that the Earth is round.

11. It is possible to see things that happened millions of years ago.

12. There are stars older than everything in the entire Universe.

[Answers appear at the bottom of page 3.]

1 870:010 “Astronomy,” 3-4 CH Latham 125 10:00 AM M-W-F or 1:00 PM M-W-F 2005-2006

SYLLABUS

Welcome to 870:010. This is an exciting time to take "Astronomy." Just recently, two robot spacecraft were simultaneously busy at work: one roving the dunes of Mars, the other photographing the surface of Saturn’s “moon” Titan for the first time. New planet-like bodies were discovered: small ones in the far reaches of our Solar System and huge ones orbiting stars other than the Sun. And evidence mounts for the existence of anti-gravity! We will be learning about all these things and more. First, though, here is your guide to making the course "user friendly."

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QUICK INDEX:

If you have questions about..... Look on page number.....

How To Find Your Instructor 3

What the Course Is About 4

Course Prerequisites 6

Using Your Textbook 7

How Your Grade Will Be Assigned 8

How Exams Work 8

How Homework Works 10

Others Things Required of You in the Course 10

What Topics Will be Covered When 14

Laboratories (for those enrolled for 4 credits) 18

Reading assignments 27

Hints 40

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2 INSTRUCTOR: Dr. Thomas Hockey, Professor of Astronomy Department of Earth Science office: Latham 112 phone number: 273-2065 (3-2065 on campus) if no answer, call: 273-2759 (secretary) FAX: 273-7124 campus mailing code: 0335 electronic mail: [email protected] (checked once a day)

My WWW Page is at http://www.earth.uni.edu/tah.html.

My office is down the hall from your lecture room (west) almost to the end. It is on the left.

On the way, you will pass the Department of Earth Science Office (a good place to leave a message): Latham 121, the windowed office on the right. It is open 8:00 - 12:00 noon and 1:00 - 5:00 PM every weekday.

OFFICE HOURS: 11:00 - 12:00 M-F or by appointment. You also are encouraged to simply drop in whenever I am there. Don't feel that you need to restrict your self to the scheduled office hours. Students always have priori- ty in my office unless I'm just stepping out the door (to go to class, for instance) or on the phone to Africa or some place . . .

If you knock on my door and there is no answer, yet there are signs of occupancy (door open, light on, etc.), give me a minute. I probably have just run a brief errand elsewhere in the building. Feel free to put a note on or under my door, too. Keep in mind that, being an astronomer, I often work at night! If you want to get in touch with me during the evening, calling my office is worth a try.

This class is designed to work in variety of ways: lecture, your textbook, etc. It is normal and anticipated that some things won't "click" via these methods. I expect to see a lot of people in my office over the course of a semester, to go over material one-on-one. This will range from answering a quick homework question to paraphrasing an entire lecture--whatever you need.

Occasionally, I will have to miss my office hours, but I will try to tell you ahead of time, in class.

1. T 2. F 3. T 4. T 5. F 6. T 7. F 8. T 9. T 10. F 11. T 12. F

3 OBJECTIVE: We will be taking a tour around the Universe, stop- ping every once in a while to take a look at how we arrive at astronomical knowledge. We will take care to note that astronomy is not a dead body of knowledge, but rather a dynamic on-going process. New discoveries and understandings will be pointed out as will things that remain very much a mystery to us. All this is to say that, far from doing something specific to one narrow discipline, we will be doing what each of us thinking human beings has been doing since the beginning: trying to figure out where we are and what the "rules" are. In this regard, astronomy is a very human endeavor.

On the practical side, astronomy is a liberal-arts course. I will not claim that it will be of vital use to you in day-to-day life, nor do I feel that I need to. While this course may help you to improve your three-dimensional thinking or your reasoning skills, its main function probably will be to help you "tap into" our culture, that is, understand astronomical allusions and concepts that appear in writing, conversation, or the evening news, as well as to aid in your personal maturity of thought.

I have several major goals for this course. There are a number of ideas that I hope that you still will consider even when much of the specifics of 870:010 are forgotten. Whether explicitly or implicitly, we will return to them again and again throughout our semester together. A few of these are:

1. Our senses provide direct information--limited by resolution--in two dimensions. But space is in 3-D! It is often difficult to infer the third dimension. Some times we have to use angular measurements when absolute measurements of length, height, and width are unobtaina- ble.

There are two different ways of viewing a thing in the Universe: as an object projected into the sky or as a place in its own right. Our impressions of these things often differ from the two perspectives. Furthermore, because something is impossible to visualize does not necessarily mean that it does not exist.

2. The story of many natural systems is one of gradual change punctuated by occasional, sudden, course-altering events. Both equilibrium and cycles are common in the Universe.

Objects such as stars and planets are not unchanging; they evolve with time. Their appearances today offer clues as to their histories.

3. The Earth is one data point. The Sun is one data point. Terrestrial life is one data point. To understand fully our environment and ourselves, we must seek other data points.

Our lives and environment here on the Earth bias us as to what a "typical" place in the Universe is like. Our

4 ability to affect the Universe is minuscule. The world will continue with or without us. It is in our own self interest to maintain the unusual set of conditions that allows life on the Earth. There is no one that we know of to "bail us out" if we fail. And there is no place else on the seeable horizon to go.

4. Traveling in the Universe is difficult; observing the Universe is comparatively easy.

5. Unlike some other scientific disciplines, significant contributions can be made in astronomy by individuals without elaborate equipment or lengthy academic credentials.

At the end of the semester, look back at this short list and reflect on how these ideas have been developed and whether or not you agree with them.

A SUGGESTION: We are at a disadvantage in that our astronomy class meets in an enclosed lecture hall during the daytime. Because of this, you will unavoidably miss out on some of the fun of astronomy, that is, actually going out and observing the heavens yourself. You will be encouraged to do this some on your own. (You might want to check out the Sky Maps in your textbook.)

If you feel that you would enjoy some more of the "practical" nighttime astronomy that we cannot always cover in this class (learning the constellations, telling time and direction from the sky, etc.), let me know. The Earth Science Department occasion ally offers as 870:113, "Topics in Earth Science," a course in naked-eye astronomy. With enough interest, we may be able to schedule it in the near future.

Other UNI Astronomy Courses:

∑ 870:058 Astronomy Field Trip (2 credit hours)1 ∑ 870:151 Planets (2 credit hours)1 ∑ 870:152 Stars (2 credit hours)1 ∑ 870:153 Galaxies (2 credit hours)1 ∑ 870:154 Observational Astronomy (2 credit hours)2

1 prerequisite: 870:010 2 prerequisite: 870:010 (four-credit version)

5 PREREQUISITES: High School algebra and geometry. I will assume that you:

½ understand proportions can solve an equation for a variable can solve simultaneous equations with two variables ± are familiar with simple geometric formulae (e. g., perimeters, areas, and volumes for simple shapes) ° can work in degree measurement (360 degrees in a circle, 90 degrees in a right angle, 180 degrees in supplementary angles, etc.)

In addition, it will be helpful if you know how to use certain functions on your calculator--if you don't have one, I suspect you will want to borrow one for the semester--such as the "squared," "cubed," "square root," "cube root," and "exponent" buttons.

Please let me know if you need help with anything mathematical.

You may want to refamiliarize yourself with the idea of latitude and longitude on the Earth--we will be applying it early in the course.

OUTLINE: I will try to follow the attached schedule of lectures, exams, and other class presentations (page 14) as closely as possible. Note the days listed with the topic "Etc." We will use these class times for supplemental activities, review, or to go over topics for which we may not have had adequate time previously.

When we are operating in a "lecture format," I often will define new subjects and terms on the chalkboard or overhead projector. These "working definitions" do not replace the more exact wording in your textbook glossary.

Do not make the mistake of copying down in your notes only that which I write out for you. Much important information will be conveyed verbally, and you will want to take notes during my oral presentations. This will hold true during slide and videotape presentations as well.

BY THE WAY: Besides fulfilling a General Education requirement, did you know that this course may be applied to several degree programs? See the hall display (between your lecture hall and my office), or me, for details.

6 TEXTBOOK: The Cosmos: Astronomy in the New Millennium, Second Edition, by Jay Pasachoff and Alex Filippenko. Thomson. (2004). Successful completion of this course probably will require reading nearly all of this 400+ page book.

This particular text has been chosen because it is readable, well illustrated, and (most importantly in a quickly developing discipline like astronomy) up-to-date. You will find that many of the four-hundred slides that will be presented in lecture also appear as pictures in the textbook.

To guide you in your reading, you are given a list of reading assignments (starting on page 28). It will be to your advantage to have read the assignment for a particular day before that day's lecture. In fact, I will assume you have done this. Each lecture will cover a lot of ground and will probably be difficult to follow if the lecture is your first introduction to the material.

While the lectures and textbook readings are intended to comple- ment and reinforce one another, you will be responsible for material in the reading assignments not covered in lectures and, likewise, material presented in the lectures that does not appear in the text.

If you run across an instance where the text and the instructor seem to differ, I will expect you to bring it to my attention as soon as possible. Every textbook almost certainly contains "typos," and both the author and I would appreciate your help in ferreting them out.

Read your text critically, particularly the numbers. You may be surprised to learn that many of the physical quantities we use in astronomy are not well known yet. Often the numbers stated in the book and in class are approximate or a most recent estimate. We will round numbers often to the closest power of ten. These rounded numbers still will give us a good sense of what is going on and will be easier to remember.

In addition to your textbook, I recommend that you purchase a three-ring binder in which to keep exams, homework, and other handouts. These materials will be punched for this purpose.

I will bring graded materials to class at least twice. If you do not retrieve them at those times, you will need to pick them up "receipts" for your scores earned. Please pick up only your own materials.

7 GRADES: Your grade for the course will be based on your earned percentage (see discussion of exams, homework, and other requirements below) and will follow a scheme something like this:

A=90% & above B=80% & above C=70% & above D=60% & above

This system has the advantage that it does not require some arbitrary number of "points" for a particular grade (347 points = A, 289 = B . . . that kind of thing)

I reserve the right to change the grading scale by lowering the numbers if I feel that this is necessary. "A"'s will not be easy to get and, hopefully, neither will "F"'s.

(The following standard rounding rule is used . . .

Example: 89.4 = 89%; 89.5=90%)

I do not post grades, for reasons of confidentiality. Just stop by and ask.

EXAMINATIONS: There will be four, forty-to-fifty-minute exams given during the semester. There will be no comprehensive "final" per se. Individual rescheduled exams, due to illness, require a physician's note.

You will have all class period to work on an exam. If you are enrolled in the 3-credit version of this course, each exam will count as 20% of your course grade. If you are enrolled in the 4- credit version of this course, each exam will count as 18% of your course grade. All exams must be completed in ink.

Each exam will consist of many multiple-choice questions (four possible responses each). While I realize that some people do not feel that they "test" well in this format, it is a necessary one for a class of this size and in order to meet the two requirements for an exam that I believe students desire: rapid turn-around on the exam results and the opportunity to review the exam afterward, explicitly, for future reference.

Example Exam Questions

A theory of the nature of the Universe is termed: a. a cosmology. b. a constellation. c. a deferent. d. an epicycle.

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8 When light strikes a curved mirror, as in a reflecting telescope, its angle of reflection a. always equals its angle of incidence. b. is greater than its angle of incidence. c. is unpredictable. d. None of these. ______

Which one of the following is impossible to see in the night sky? a. the shape of the Moon b. the color of a star c. the motion of a planet (over several weeks) d. the size of a star ______

The questions that I ask will require some memorization of facts. While memorization is considered (by some) a lower-order mental skill, and the very word "memorize" has unpleasant connotations, it is simply impossible to discuss the subject of astronomy without some basic facts at our common disposal.

But just remembering information usually will not be sufficient to adequately choose between the four possibilities on an exam question, and it is not the main purpose of the course. You will need to make judgements about what you remember. The purpose of science is to explain, and explanation requires decision making in the process of sorting out the available facts. I will test you on your ability to render judgements using the proper remem- bered items at the proper time in the proper pattern. By doing this, you will demonstrate that you understand the purpose of, and have successfully completed, this course.

You will not be asked to work out quantitative problems on the exams. There simply is not time. Instead, you will be given an opportunity to do this on the take-home homework assignments.

If you find a test question for which you absolutely cannot choose between two "best" answers, this means that there is a mistake in the test item. In the rare case that you believe this has happened, select one answer to place in the answer blank. (Historically, people tend to choose the intended correct answer.) Then write me a short note on the back of the test form, citing the number of the offending test item and presenting a brief rationale for there being two equally "best" answers.

Chance of "Accidentally" Passing this Course Odds = 4:1

↓ Odds = 4:1=

based upon random guessing on exams--not recommended!

9 HOMEWORK: Note: This page only applies to those enrolled in the 3-credit version of this course.

Our discussion of astronomy in class will be largely qualitative. Yet it would give you the wrong impression of modern astronomy to suggest anything other than that much of our description of the Universe is based on mathematical computation. Homework is designed to give you a feel for how astronomers can learn from calculations. It is not (necessarily) preparation for test.

There will be three homework assignments during the semester, in-between the exams. An assignment will be due and collected at the very beginning of class, one week after it is handed out. As was suggested above, these assignments will highlight the quantitative aspects of the course (i. e., problem solving). Each home work assignment will count as 5% of your course grade.

Please work out homework problem solutions on the original form (or a photocopy of the form) handed to you. Extra copies will be available.

Homework will be returned to you with the correct solution written out if you have gone astray. I also will be happy to work out homework problems on the chalkboard after they have been returned to you.

In the interest of fairness, scores will be penalized on late homework. This is so that everyone has the same amount of time to work on the assignment. The later the homework, the greater the penalty. Late homework is always accepted, however, and will always receive some score.

Homework turned in late will probably be returned to you late. This is not an additional penalty or "punishment;" it simply reflects the mechanics of the grading process whereby assignments are marked in "bunches." (Homework turned in early, on the other hand, will be returned promptly and is appreciated!)

I suggest that you keep handy your old homework assignments, after they are returned to you, and all the lecture notes that you have made during the semester. You may be helped on homework assignments made late in the class by examples and formulae presented early in the class.

OTHER REQUIREMENTS: There are two additional course requirements:

Evening Observing Activity (counts as 2% of your course grade in the 4-credit version of this course; counts as 3% of your course grade in the 4-credit version of the course)

As I suggested before, there are some things that we simply cannot do in a lecture hall. In order to give you a taste of the observatory "experience," you will be asked to visit the

10 Observing Deck atop McCollum Science Hall. (This is the building north of Latham Hall with a dome on the roof.) You will be using UNI's computer-controlled, twelve-inch-aperture telescope to view the Moon, planets, stars, and nebulae--depending on what is in the sky at the time.

You can attend an observing session any Thursday night that school is in session (starting next week) by going to the lobby of McCollum Science Hall 2532 (Lantz Lecture Hall--this is the large room across from the mural in the north-south corridor) from where you will be guided to the roof by one of our observing assistants. The session will last about one hour.

Programs begin promptly at 8:00 PM--9:00 PM when Daylight Savings Time [DST] is in effect. DST runs from April to October. Thus, in the Fall we meet at 9:00 until it gets dark early enough to meet at 8:00. In the Spring we meet at 8:00 until it stays light long enough so that we must delay to 9:00.

As these events are also our regularly-scheduled weekly Observatory Open Houses, members of the general public will be attending as well, and you are welcome to bring friends or family along. Be advised, though, that the observatory is unheated. Dress warmly.

The observatory will be open regardless of whether or not the sky is clear (though, obviously, it will be more interesting if you can actually see the sky through the telescope). Only if the weather is bad enough that it might be dangerous to go out on the Observing Deck will a session be canceled.

You will be asked to write a report to receive credit for this activity. The report may be a simple paragraph describing what happened during the activity and what you may (or may not) have learned. (Different people will write longer or shorter reports, depending on the night.) The date you attended and your section ("10:00" or "1:00") should be included.

Your report is due on the Friday before Finals Week. For your convenience, about once a week I will bring to class a folder marked "Put Observatory Reports Here;" however, you may turn in an observing report to me at any time.

The observatory is a very tiny space, and we have a number of sections of "Astronomy." If too many procrastinate in fulfilling this assignment, we have the potential for a long end-of-the- semester line, stretching out the door, made up of people waiting to get a view through the telescope. These people might rather be using the time to study for finals or get ready to graduate. Needless to say, it would not be the pleasant observatory experience that I wish for you. (The observatory staff is authorized to limit the number of persons in the dome to twenty, too.)

In order to avoid crowding and long lines outdoors, the SPRING semester will be divided in two. If your last name begins with A - M, you are asked to attend an observing session before Spring

11 Break. If your last name begins with N - Z, you are asked to attend an observing session after Spring Break. While it is true that the first half of the alphabet gets stuck with the colder weather, the rainy springs in northern Iowa suggest that it is these persons who are more likely to encounter clear skies! Voluntary compliance with this system should make the Open Houses go smoothly, even on popular nights. (Some people elect to go twice: once early in the half-semester to which they have been assigned, so as to insure fulfilling the requirement and, if it was cloudy the first go around, a second time on a clear night to actually see something through the telescope.)

In the FALL semester, the advantage of fulfilling this requirement early is obvious: It gets pretty cold outside at night in December!

Please let me know about Thursday-night conflicts as soon as possible (e. g., another class). Those in a Thursday-night laboratory section will fulfill this requirement in lab.

Most regrettably, the Observatory is not wheelchair accessible. Please let me know if special arrangements are necessary for fulfilling this requirement.

Daytime Observing Activity (counts as 1% of your course grade in the 4-credit version of this course; counts as 2% of your course grade in the 3-credit version of the course)

The Sun is the one astronomical object we can observe in the daytime. Close to the time when we discuss the Sun in class, you will be asked to both observe and draw the appearance of the solar disk through a telescope set up for this purpose. (See the Course Outline.) A form describing how this activity works will be given to you in November/April. In case of clouds, this event may be rescheduled.

Do not attempt to observe the Sun on your own. Observing the Sun without proper filters may result in eye damage.

(Use the UNI campus map, on the following page, to find where these two observing activities will take place.)

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LABORATORY: As per the UNI Catalog, students wishing to fulfill their Liberal Arts core laboratory requirement in astronomy must take "Astronomy" and "Astronomy Laboratory" concurrently (or take the four-credit "Astronomy" that includes lab). These courses routinely fill early during the registration process. For the foreseeable future, we anticipate no more than fifty-four lab openings per semester. Please take this information into consideration as you plan your degree program.

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12 "TOOLS OF THE TRADE": I would like to preview for you here a few of the major conceptual tools we will be using in "Astronomy." You will be hearing about them frequently in the class.

A scientific theory is neither a guess nor an absolute truth. It is a powerful tool, and everyone of us, whether we think about it or not, puts our faith in theories routinely during the course of a modern day.

The Universe is built on a scale of the very small and of the very large. Orders of magnitude help us in our attempt to com- prehend the extremes of distance, time, mass, and energy that we encounter in astronomy.

Sorting natural objects and phenomena into categories (classifi- cation) is a useful first step at explaining and interpreting them. Sometimes a graphical representation of their properties also is useful. We must be careful, though, to distinguish between apparent properties and intrinsic ones.

Sabin

MSH Go to Observatory here.

Solar telescope set up here.

Go to class here. LAT

A Map

13 COURSE OUTLINE

INT Introduction HIS The Early History of Astronomy KEP Tycho, Kepler, and Newton SKY Getting Around in the Sky PLA - no lecture - Visit the planetarium (Latham 105) at your prearranged time within the lecture hour. ECT The Ecliptic SEA The Seasons ASP Planetary and Lunar Aspects ECS Eclipses ETC "Etc."

This is a good time to review page 8 of the Syllabus, "Examina- tions."

EX1 EXAM I

LGT Light TEL The Telescope OVR Planets: An Overview SIZ On Size and Distance M&M Mercury and the Moon E&V The Earth and Venus MAR Mars OID 'Oids (Meteor- and Aster-) ETC "Etc." EX2 EXAM II

The course is half over! Have you been to the observatory yet? If not, review page 10 of the Syllabus.

JUP Jupiter OUT The Outer Solar System ICY Icy Satellites PLU Pluto and Stuff COM Comets SPC Spectroscopy SUN The Sun SOL - no lecture; solar observing day - DIS Star Distances STA Star Light ETC "Etc." EX3 EXAM III

Check to see what other astronomy courses are being offered in the Fall/Spring?

HRD The H-R Diagram

LIV The Lives of Stars DIE How Stars Die WAY The Milky Way GAL Other Galaxies CML Cosmology CMG Cosmogony ETI Search for Extraterrestrial Intelligence (not every semester) ETC "Etc." EX4 EXAM IV

Finals Week: (See page 15, Schedule of Classes.) We will take care of miscellaneous end-of-semester business.

TEN FREQUENTLY ASKED QUESTIONS ABOUT 870:010 ASTRONOMY

"Are the classrooms wheelchair accessible?"

Yes. There are two spots designated for wheelchairs in the first row of LAT 125 (lecture room). LAT 103 (lab room) is also accessible. The planetarium (LAT 105) has room for one wheelchair.

"Why are the reading assignments not in the same order as the book lays them out?"

I wish they were, but there is no book on the market that takes the topics in astronomy in the order in which I believe is best for students. This book comes closest.

"When can I make an appointment?"

You're actually busier than I am. (I admit it!) I don't mean that I don't have anything to do; it's just that I don't have five or more classes that require me to be at a particular place at a particular time. When you ask to set up an appointment, I'll probably turn right around and ask you when you would like to make it. You might have a time in mind. If it's not 10:00- 11:00 or 12:00-2:00 M-F, it's probably a good time.

"Does the class get harder or easier as the semester progresses?"

This is a hard one. I probably have to say that it gets harder in that we talk about more and more abstract things as we go along. We don't dump black holes and the expansion of the Universe on you right away--we start with familiar things (phases of the Moon, Earth-like planets, etc.) Past exams suggest that on the average (and everything else being equal), people's scores stay the same or go down slightly each unit. Keep in mind, though, that what happens on the average may have nothing to do with your performance.

"Do you draw exam questions from the book or the lecture?"

I try to come up with questions about material that has appeared both in the book and the lectures, though something may be covered in great detail in the book and mentioned in passing in class or may be discussed extensively in class and allotted only a line in the text.

"Do you grade on a curve?"

No. A real grading curve assigns grades according to a predeter- mined statistical process. The result is that at the outset it is known that a certain small number of people will get "A"s (and a certain small number of people will get "F"s). Likewise, as many people get "D"s as "B"s. In an absolute grading system, like ours, everyone starts out with at least the possibility of getting a high grade.

"O. K., but do you intend to lower the grading scale?"

I have done so only when something unusual has happened during the semester to, in my opinion, make scores lower than they would normally be. Most of the time I have not. It would be unwise, therefor, to assume that the grading scale will be anything other than what is printed in the Syllabus. In any event, I would not make a decision on adjustment to the scale until I compute final grades, sometime after the last exam.

"Do I have to come Finals Week?"

The University requires that this course meet during its scheduled final examination period. However, assuming we have re- mained on schedule, you will have met all the graded requirements for the course before this time. In other words, I have to be here Finals Week. Closer to the end of the semester, we'll discuss what we might do on our "final exam" day, and you can decide for yourself.

"Do you assign "+" and "-" grades?"

Usually, except if everybody would end up with a minus. Because my grading scale is fixed, this is the one place where I allow myself some small latitude to evaluate individuals' overall performance. There is no set formula, and I do not assign the "+"s and "-"s until after I have calculated final letter grades. In general, those of you high in your grade bracket will get a "+", and those of you low in your bracket will get a "-". (I have been known to give "A+"s, but they don't seem to get recorded on students' transcripts in the Registrar's Office!)

"Besides UNI, where can I go locally to learn more about astronomy?"

The Grout Museum (Waterloo) houses a planetarium and astronomy exhibits. It also sponsors telescope-observing sessions and loans portable telescopes. The Des Moines Science Center is home to a large planetarium, too.

[Note: The Lab Syllabus applies only to those enrolled in the 4- credit version of this course.]

LAB SYLLABUS

YOUR CLASSROOM: We will not spend all our time in Latham 103. Normally the room door will be unlocked. Keep track of your valuables. Also, Latham Hall is fairly distant from both dormitories and parking lots. In consideration of the hour at which we will be dismissing, I recommend that you find someone with whom to walk across campus after class.

If you are seated in the back row of Latham 103, be careful that your chair does not rub against the "moonscape" mural.

OBJECTIVE: We will be examining the tools and techniques one can use to explore the Universe without leaving the Earth. In the process, you will become more familiar with finding your way around the night sky. Even the indoor exercises will be selected with this end in mind. Astronomy you can do by yourself standing in your own backyard will be an emphasis of this course.

Also, you will have the opportunity to practice communicating quantitative measurements to others, i. e., writing a laboratory report. We will point out how dealing in a practical sort of way with actual physical measurements differs from the more pristine manipulation of pure numbers found in a mathematics class. The techniques involved here are general and may be applied many places outside of Astronomy Laboratory.

A laboratory differs from most of the courses you have taken previously. This is because, in lab, you will not be told each step necessary for completing an exercise. An important aspect of lab is to encourage you to practice coming up with ways to solve a problem on your own. Thus, you may be asked to determine some physical quantity by making a certain measurement--without each of the procedures between your measurement and the desired quantity being spelled out. In other words, you will be asked to come up with many steps yourself. Indeed, different people will solve a given problem in different ways. This is as it should be for it is how scientists actually approach physical problems.

This kind of exercise may seem frustrating to you at first, especially if you get "stuck." When this happens, make sure you

18 ask for help. This way we can get you "unstuck" as quickly as possible.

TEXTBOOK: The Sky Gazer's Almanac (Sky Publishing Corporation). Please pick up the 870:010 Astronomy course packet (Hockey), as well. (It is at CopyWorks, on the corner of 23rd and College; specify your lab section—Monday, Tuesday, Wednesday, or Thursday.) Bring the packet to each lab meeting. (In addition to your packet, you will occasionally be asked, with suitable notice, to bring other materials along.)

You will find it useful to bring an electronic calculator with you to class. This need not be a fancy one--most of the time you will just need "+," "-," "x," and "/." Simple calculators cost less than $5.00 these days.

A small flashlight ("penlight") also can come in handy.

WHAT TO EXPECT: A typical lab night will start with a brief discussion of laboratory techniques and an introduction to that evening's exercise. I often will not be able to tell you in advance with certainty which exercise we will be doing on a given night. The most likely reason for this will be the weather. We will try to do an outdoor lab every time, but, unfortunately, often (in the spring, very often) it will be cloudy. If this is the case, we will do an indoor lab. Thus, there will always--barring tornado warnings!--be a lab regardless of the weather.

You may be asked to work individually or with a group to complete the exercise. Normally, though, there will be no more than two people working at a single telescope.

Once you are given your lab exercise, you will have the rest of the class period to work on it. Unless otherwise requested, you are expected to turn in the completed assignment, based on the exercise, that night. After you are finished, you are free to leave unless you are asked to remain for something special. (I will always reserve the right to use the entire class period--maybe even ten minutes extra, occasionally.) Be sure, though, that your lab assignment is as complete, orderly, and neat as possible before turning it in.

When we take out telescopes, the instruments we will use most often are the six-inch-aperture reflecting telescopes. Take caution moving them; they are heavy. (These 'scopes are best grasped at the black mount, below the white mirror tube.) Be especially careful of the mirror, located at the bottom of the telescope tube.

In addition to lab exercises, we will take some time to get acquainted with the sky. These activities are designed to help

19 prepare you for your lab exams. (See "Requirements" page 20, below.)

LABORATORY REPORTS: While you may have been exposed to a laboratory report "formula" in junior- or senior-high school, I find that these formats are forced and do not reflect the way scientists report on their work in the real world. A laboratory report is just good communication. You are merely asked to describe what your purpose was in doing the activity, what steps you took, and what results you obtained. Assume, while you are writing, that the reader was not present during the laboratory, knows nothing about the exercise, and has no more astronomical knowledge then yourself. Lastly, pay attention to details. They do matter.

Sometimes, explicit discussion questions also will be assigned. In some exercises, your answers to these questions may be the only opportunity for you to interpret what you are doing in writing, and I will read these particularly carefully.

As the semester goes along, I will require more and more things to be included in a good laboratory report. (Most of these things have to do with how to handle experimental error in a real physical measurement and will be discussed as we go along.) Therefore, more and more will be required to obtain a high mark on your laboratory report, but then, you also will have more experience in writing one as we progress through the exercises.

One thing I will mention right now: Some exercises (depending on how often we get outside) will not involve an experiment or process per se, but rather will require you to report what you have observed. Whenever an exercise requires you to observe something in the sky, the following information should be recorded: the time and date, your location, any instrument you may be using, the condition of the sky, and where the object you are looking at is in the sky.

I consider developing our powers of observation to be an important task in this course. The view through a telescope is a good thing to practice on because of its relative simplicity. Some questions that you may find helpful to ask yourself, while looking at and writing about something through a telescope, are: What is its apparent size? Does it have a shape? If so, what is it? Is it uniform in appearance? Is its border sharp or dif- fuse? How bright is it? What color is it? Is it moving? What is the background like? Etc. Ask me or my assistant for other suggestions about specific celestial objects as you locate them with your telescope.

Remember that your Laboratory Assistant is a student like you, who has taken and done well in this lab before. Use him or her as a resource!

Lastly on the subject of laboratory reports, please write them in

20 ink. (Drawings may be made in pencil.)

REQUIREMENTS:

Lab and quiz scores will be averaged and count as 25% of your 4- credit 870:010 "Astronomy" grade.

Lab Exams - There will be two quizzes, one near the middle of the term and one near the end of the course, to test your practical knowledge of the sky. These will be conducted orally outside looking at the sky or, if necessary, using a planetarium (or slides). During each quiz, you will be asked to identify six bright stars and six constellations by name from memory. The idea is not to memorize a great many things but rather to know where a few things are well, under a variety of conditions. You will give to the instructor a list of the objects you intend to identify before you go out to take the quiz. The stars and constellations that appear on your list are up to you. The only restriction is that there are no duplications on the mid-term list and the end-of-term list. You will have twenty minutes to complete a quiz (but probably will require much less time). Each quiz will count as double the value of a laboratory exercise. You are expected to spell and pronounce the names of your stars and constellations reasonably correctly.

If we are not doing enough outside or in the planetarium to help you prepare for these quizzes, please let us know. Pointing out stars and constellations is actually one of my favorite parts of the lab and, more than anything else that we will do, involves practical knowledge you can bring out of Astronomy Laboratory that can be used, without preparation or equipment, for the rest of your life. When something is pointed out in the sky and you cannot see it, speak up. It is very difficult to get eighteen people all looking in the same direction! We will be glad to point out anything in the sky to you, individually.

You will need to spend some time outside class familiarizing yourself with the stars and constellations and with where they are in the sky. (Remember, this changes from hour to hour and from night to night.) In a sense, this is an on-going assignment throughout the semester. Please do not wait until right before the quiz to practice. It may be cloudy all that week!

Labs - Each week there will be a lab assignment for you to complete. Each lab will count the same even though by necessity some exercises will be more difficult and/or time-consuming than others. This will help both you and me keep track of your progress more easily and will avoid penalizing the person who is home sick with the measles during a lab that happens to count 20% more than the "lucky" person who breaks a leg on a night with a lab worth only 2%.

Laboratory reports will be graded much like any written assignment (e. g., an English paper), that is subjectively. This must be, for in the case of a real physical problem, each of you may proceed differently and arrive at different (but correct) solutions. Your score (usually on a scale of 1-10) reflects my opinion of the quality of your work and is not necessarily an indica- tor of how many things you got "wrong." "Half a point off for this" and "three quarters off for that" becomes tedious and, ultimately, meaningless. A “perfect 10” will be reserved for exceptional reports that show scholarship above and beyond "getting all the answers right." In short, you will find that a modest amount of work will be required of you during each lab exercise but that I ask for excellence in what I do require.

GRADING CRITERIA (LABORATORY REPORTS): In the spirit of the preceding paragraph, use these items as a guideline in assessing your work.

I. How well does the report reflect understanding of the purpose of the assignment?

II. Is the report legible and understandable?

III. Does the report adequately explain what took place during the course of the laboratory exercise?

IV. Does the report suggest patience and care in undertaking the exercise on the part of the student?

V. Are astronomical facts and theories applied correctly?

VI. When explicit answers are required, are they correct and presented in the proper format? Are computations leading to numerical answers shown?

VII. When explicit questions are asked, does the report answer the questions and do so in a logical fashion?

VIII. When observations are required, are all the observable properties discussed? (See "Laboratory Reports" above.)

IX. Is the report complete? Is it neat?

X. Does the report reflect any innovation, or effort to pursue the laboratory exercise, on the part of the student that goes beyond the minimum requirements stated in the instructions or in class?

***. While grammar and spelling are not graded explicitly, I will make the corrections, or suggestions for corrections, that I see are necessary.

22 MAKING UP WORK: Every once in a while someone must miss a lab with some bona fide excuse. Yet because of the format of our class, it is virtually impossible for you to "make up" a missed lab. Alternate evening times are difficult to arrange, and a lab section meeting on another night is almost certain to be doing a different exercise than the one you missed. Therefore, there will be no made-up labs. However, I will drop one of your lab scores--either that of one you had to miss or, if you attended all of them, your lowest score.

ATTENDANCE: Obviously, you can tell that I consider it important for you to attend labs. In this class, you cannot learn by reading about it; you've got to do it! Naturally, though, I am willing to take into consideration exceptional circumstances. If this applies to you, please bring your situation to my attention as soon as you are able (beforehand, if possible) so that we have the best chance of working it out.

A REMINDER: It's cold out there! Seriously, dress warmly. What works for running across campus from classroom to classroom just does not cut it. At night when the sky is clear (and when we will be outside) the temperature drops quickly. Also, the nature of astronomical observation (i. e., standing in one place for ex tended periods of time, usually away from any convenient wind break) can make for an uncomfortable, instead of enjoyable, evening if one is not properly prepared.

. . . AND FINALLY: The sky subtly rewards those who observe it. The views you see of the stars and planets through a telescope may disappoint you at first if you are used to the dramatic space-probe-produced and computer-enhanced photographs that appear in textbooks or on television. But one of the joys of observing is that the longer you look and the more you learn, the more you will "see." Be patient. Remember, what you are looking at is real. It is not recorded and edited for your consumption as is so much of what we experience in today's world. You are watching the Universe "live" . . .

Requirements for the UNI Astronomy Minor

¸ 870:010 (4-credits) or 870:010 (3-credits) + 870:011 ˝ 870:151 ˛ 870:152 or 870:153

23 ¸ 870:154 ˝ 800:060 ˛ 800:061 ¸ 880:061 (not required if student has taken 880:056) ˝ 880:130 + 880:131

SOME SUGGESTIONS AND CAUTIONS FOR OPERATING THE C-8 TELESCOPE

These miscellaneous hints are based on experiences previous Astronomy Laboratory students have had with the C-8 telescopes. Please remember always that despite their "well-used" appearance, these telescopes are delicate scientific instruments that can do truly remarkable things with only a little care and thought in operation.

Cautions L

1. When carrying a telescope case, make sure the latch is se- cured by a pin to prevent accidental spillage of the contents. Try not to lose the pin.

2. Do not lay any of the equipment, including cases, in wet grass or snow. The feet of the tripods are exceptions, of course.

3. Keep track of the large rubber band holding the tripod legs together. The "octopus" tripods are stored with the legs flipped over the "head."

4. Avoid getting fingerprints on the telescope corrector plate (aperture window).

5. Never allow the telescope to move on either axis if locked. Unfortunately, this is the most common way of abusing the telescope.

6. When adjusting the alignment of the sighting telescope, make sure that the set screws do not scratch the telescope tube.

7. Do not try to clean an eyepiece or any part of the telescope optics. These surfaces are easily scratched and require a special tissue and fluid to clean them.

8. When putting eyepieces away, see that their optical surfaces are protected by plastic, cardboard, or foam. When putting the telescope away, make sure that no force is being exerted on the sighting telescope by the case or its lid.

9. If you drop anything on the dark ground, feel free to call an instructor over with a bright flashlight to help look for it. You will not suffer any horrible consequences for misplacing something, and searching immediately increases the chances of finding the lost part.

10. A lot of the telescope parts are small, and there are quite

24 a few of them--yet we need them all. Please check your pockets and the ground around your telescope before packing up.

11. Try to keep telescope accessories together and in cases when not in use. This will reduce the likelihood of stepping or tripping over them.

Suggestions

1. If the telescope is too low to the ground, check if your tripod comes with extendable legs.

2. Note that the set of bolts for attaching the telescope to the wedge and the set of bolts for attaching the wedge to the tripod are not interchangeable. Make sure that you have the right-sized bolts for each purpose.

3. There are two sets of bolt holes on the top of the tripod. If, while attaching the wedge to the tripod, the bolts do not "grab," you are using the wrong set of holes. Rotate the wedge a couple of inches around the circumference of the tripod top, and you will find the correct set of holes.

4. Once it is set up, test the movement of the telescope. Does either end sag under its own weight? If so, ask for instructions. The telescope must be able to point anywhere in the sky and stay there unattended (except near the horizon). You will not be able to hold the telescope steadily enough to keep it pointed at a celestial object if you are fighting gravity.

5. If the sighting telescope hangs under the main telescope in an awkward position, turn the main telescope 180 degrees on both axes so that the sighting telescope swivels to the top.

6. Align the polar axis of your telescope and check the alignment of the sighting telescope--first thing! These extra steps before observing will ultimately speed up the process of finding (and keeping) celestial objects in view.

7. As a first rough attempt at pointing the telescope, sight along the telescope tube itself. When using the sighting telescope (as well as the main telescope), to find things in the sky, remember that the direction an object moves in the eyepiece is not necessarily the physical direction you are moving the telescope. There are one, two, or three mirrors between you and the object, and these reverse the apparent direction of motion.

8. Searching the sky for an astronomical object with an out-of- focus telescope is next to useless. If you see nothing through the telescope, chances are that it is not in focus. There are enough stars just too faint to be observable with the naked eye that random sweeps with an eight-inch-aperture telescope ought to stumble across several of them. However, if the telescope is out of focus, starlight is not concentrated in a point and, instead, is spread out over a circle too dim to see. Remember, a star should always appear as the smallest point possible to assure proper focus.

9. If your telescope is out of focus, check to make sure that both the eyepiece and the diagonal are slid as far as possible into their receiving sleeves. Do this before turning the focus knob through many rotations; you may simply be running it further and further out of focus.

10. While scanning the sky with your telescope, if you see a fuzzy object that looks like a donut, stop! This is an out-of- focus image. You are actually seeing the mirror itself and the back of the secondary (the dark "donut hole"). Adjust the focus until the "donut" becomes smaller, brighter, and sharper and loses its "hole."

11. Finally, be patient with the telescope. Even if your instrument is in focus and in good working order, it will still probably take you some time to find an object in the sky. The field of view (that part of the sky that the telescope "sees") is exceedingly small, and it will be very easy to just miss your object. Your skill at finding things probably will increase as the semester goes along and you get a "feel" for the telescope, but even then there will be those times when you cannot quite get it--at least right away. I still have nights when it takes thirty seconds to point telescopes #1-#7 and then ten minutes to point #8!

The 9:30 PM Promise

Don't panic. If, after sincere effort, you have not located anything through your telescope by twenty-minutes before the class period is up, I will do it for you. Nobody leaves "empty handed!"

A FEW WORDS ABOUT YOUR READING ASSIGNMENTS

You won't hear me saying a lot about your textbook reading assignments, but do not make the mistake that a few students do each semester and not read them. Unless you ask questions about the readings (the end of the class period is an excellent time to do so), I will assume that you have them pretty well in hand.

The order of the subjects of the sections assigned is the easiest one to develop in lecture. Occasionally, the assigned text will refer to a passage that you haven not read yet. If this is troublesome, you are encouraged to use the glossary and index and refer to the as-yet-unassigned pages. There is no rule against reading more of the book than you are assigned or past the text you are assigned. Indeed, many of you will want to read the text more than once. For instance, some students find reading the material again in order, chapter-by-chapter, to be useful before exams.

All reading assignments are from Pasachoff & Filippenko 2004. Page numbers refer to the bold-face-titled sections beginning or ending on that page. (Sections also are listed in the “Detailed Table of Contents," within the book’s frontmatter.)

In addition to the sections that appear on the reading lists, your text provides "Concept Review," "Questions," and "Topics for Discussion” sections. While unassigned, these are an obvious resource. "Boxes" also are optional reading.

On the bright side, the explicit assignments are not quite as long as they appear. Our text was chosen, partially because of its wise and ample use of photographs, tables, and figures spread throughout its pages!

[Following each reading assignment below, I have included an anticipated outline of that day's lecture.]

27 READING ASSIGNMENTS - UNIT I

After some introductory remarks, in this unit we will trace the history of astronomy. We then will take a look at our sky, as seen by the naked eye.

INT Introduction Text pp. 1-5; 10-16

HIS The Early History of Astronomy, or "How Astronomy through the Ages Has Been Largely a Search for Our Place in the Cosmos" text pp. 16-19; 77-81

I. Observable Facts II. Peoples' Views of the Universe A. Early Civilizations B. Eudoxus and Aristotle

KEP Copernicus, Tycho, and Kepler, or "How a Few Simple Rules Govern the Movement of Just About Everything" text pp. 81-88

I. Nicholas Copernicus II. Tycho Brahe III. Johannes Kepler A. Kepler's First Law B. Kepler's Second Law

SKY Getting Around in the Sky, or "How the Motions in the Sky Are as Regular as Clockwork (Literally)" text pp. 64-66

I. The Appearance of the Sky Throughout the Night A. Your "Personal" Coordinate System B. The Celestial Sphere II. The Appearance of the Sky From Different Places on the Earth

ECT The Ecliptic, or "How the Sun Appears to Move through the Sky" text pp. 66-68

I. The Appearance of the Sky Throughout the Year II. Precession III. Problems with Astrology

SEA The Seasons, or "How Something as Everyday as the Changing Seasons is Intimately Connected with Astronomy"

28 text pp. 68-74

I. The Obliquity of the Earth II. The Seasons A. The Location of the Sun B. Temperature C. The Number of Daylight Hours

ASP Planetary Aspects, or "How Mere Geometry Radically Changes the Appearance of the Moon" text pp. 55-58

I. Sidereal Versus Synodic Month II. Phases of the Moon III. Inferior and Superior Planets

ECS Eclipses, or "What is the most Spectacular (or Frighten- ing) Thing You Can Watch in the Sky" text pp. 58-62

I. Eclipses of the Sun and Moon A. The Solar Eclipse B. The Lunar Eclipse II. Recent and Future Eclipses

MAJOR CONCEPTS - UNIT I

The history of astronomy has seen many peoples' attempts to construct a cosmology, or theory of the Universe, that satisfac- torily described what they could see in the sky.

Johannes Kepler was able to model a Copernican (heliocentric) cosmology, based on orbital ellipses and planets "sweeping out" equal areas in equal intervals of time, that successfully ex- plained Tycho Brahe's positional observations.

There are two ways of mapping the sky: on the celestial sphere and using a system of coordinates based on one's own zenith and horizon.

The calendar is based on the Sun's and Moon's apparent motion across the sky with respect to the stars, but we now know that it is really the Earth (us!) that is moving in our Solar System, and not the Sun.

The seasons are caused by the obliquity of the Earth and produce longer/shorter "days," require the altitude of the Sun in our sky to vary, and result in greater/lesser warming of the Earth's surface.

The Moon's phases depend upon how much of the lunar nearside is illuminated by the Sun, while eclipses are produced by either the

29 Moon's shadow being cast on the Earth (solar eclipse) or the Moon itself traveling into the shadow of the Earth (lunar eclipse).

The relationship between a planet, the Sun, and the Earth deter mines how and where the planet will appear in our sky.

30 READING ASSIGNMENTS - UNIT II

We will begin this unit by looking at our principal source of information about the Universe: light. Afterward, we will embark on a tour of the planets, and other bodies, close to the Sun.

[The SPRING semester version of the course will meet one less time during Unit II. This is to accommodate the annual Earth Science Update Conference (for Iowa teachers) in LAT 125. UNI teaching majors are invited to attend; see your instructor.]

LGT Light, or "How Virtually Everything We Know About the Universe Comes to Us Via Light" text p. 21

I. The Nature of Electromagnetic Radiation II. When A Ray of Light Strikes A Surface A. Reflection b. Refraction

TEL The Telescope, or "How and Why Astronomers Greedily Gather Light" text pp. 35-44

I. The Refracting Telescope A. Light Gathering B. Magnification II. The Reflecting Telescope III. Examples of Telescopes

OVR Planets: An Overview, or "How Categorizing the Planets Is the First Step Toward Understanding Them" text pp. 91-95 (+ review Kepler’s Third Law)

I. Kepler's Third Law II. Properties of Planets A. Orbital Distances B. Sizes C. Density

SIZ Of Size and Distance, or "How Our View of a World from Afar Provides Insight into the View from Up Close" text pp. 88-91

I. Physical Measurements of Objects that can be Made From the Earth A. Planetary Distances B. Astronomical Diameters

M&M Mercury and The Moon, or "How Planetary Astronomy Shows

31 Us Other (Failed) Worlds with which to Compare the Changing Environment on the Earth" text pp. 106-118

I. Mercury: An Example of a Terrestrial Planet II. Planetary Satellites: Rotation Period = Revolution Period III. The Moon A. Seen from the Earth B. Lunar Exploration

E&V The Earth and Venus, or "How Planets, Like Living Creatures, Evolve with Time" text pp. 97-106; 118-124

I. The Earth: An Active Planet A. Planetary Differentiation B. Geologic Activity C. The Earth Seen from a Planetary Perspective II. Venus A. Planetary Rotation B. The Interior of Venus C. The Atmosphere of Venus D. The Surface of Venus III. How Venus, Mercury and the Earth Differ

MAR Mars, or "How Life is the Product of Specific Astrophysical and Geological Processes" text pp. 124-131

I. The Present State of Mars A. Similarities Between Mars and the Earth B. Differences Between Mars and the Earth C. The Interior State of a Planet II. The History of Mars A. Evidence for Water B. Evidence for a More-extensive Atmosphere C. The Search for Life III. The Future of Mars IV. Mars: A Lesson for Observers

OID 'Oids (Meteor- and Aster-), or "How Astronomical Objects May Have an Impact on You (Literally)" Text pp. 177-186

I. "Smaller" Terrestrial Bodies in Space A. Asteroids B. Meteoroids C. Micrometeoroids II. Planetary Impacts (e. g., on the Earth) A. Results of B. Evidence for

MAJOR CONCEPTS - UNIT II

Light travels in a straight line unless it is absorbed, reflect- ed, or refracted.

A telescope gathers light with an objective lens or mirror--the greater the objective area, the brighter an object will look in the eyepiece of the telescope.

The planets can be classified according to whether they orbit the Sun close to each other in the inner Solar System or are spread out in the outer Solar System, or whether they are large or small, but the most physically significant way to classify the planets is according to their densities: low (jovian) or high (terrestrial).

The major terrestrial planets consist of a metal core (probably), surrounded by a dense rocky mantle, surrounded by a less-dense rocky crust. The inner layers may be solid or liquid depending upon the internal temperature.

Signs of geologic activity within the Earth include plate tectonics, volcanism, and the presence of a planetary magnetic field.

The Moon, as well as certain other planetary satellites, rotates once in the same time it takes to revolve once around its planet. The result is that any inhabitants of the planet only have the opportunity to see one half of the satellite, the nearside, without traveling into space.

Mars is very cold. Venus, on the other hand, is unduly hot because of a significant greenhouse effect operating there. Neither planetary neighbor has much oxygen, or liquid water, to support life.

If a meteoroid strikes the Earth--a common event, it may produce a meteor or end up on the ground as a meteorite. But if an asteroid strikes the Earth--an uncommon, but possible, event, there could be worldwide devastation.

33 READING ASSIGNMENTS - UNIT III

In this unit, we complete our tour of the Solar System with those bodies far from the Sun. We then introduce an important astronomical tool called "spectroscopy." This leads us to an examination of objects that produce their own light: stars.

JUP Jupiter, or "How a Planet May Be Constructed Out of Materials Other Than Rock and Metal" text pp. 135-144 (skip material on satellites and rings)

I. Jovian Planets II. The Internal Structure of Jupiter III. The Physical Appearance of Jupiter A. Belts and Zones B. Atmospheric Features

OUT The Outer Solar System, or "How What a Planet Is Made Out of Affects What We Can See" text pp. 144-158 (skip material on satellites and rings)

I. Saturn A. Appearance B. Structure II. Uranus A. Structure B. Obliquity C. Appearance III. Neptune

ICY Icy Satellites, or "How Most of the Worlds in the Solar System Are Actually Moons" Text pp. 135-158 (just the material on satellites)

I. The Galilean Satellites A. Icy Satellites B. Io II. The Satellite Systems of the Outermost Planets A. Saturn's B. Uranus's C. Neptune's

PLU Pluto and Stuff, or "How Ice Is the Common Denominator in the Outer Solar System" text pp. 163-167; 189-198 + go back and read about rings

I. Pluto II. Planetary Rings A. Saturn's B. Those of Jupiter, Uranus, and Neptune

34 C. Solar –system Cosmogony

COM Comets, or "How Objects that Appear Very Different in the Sky May Really Be Quite Similar" text pp. 167-177

I. The History of Cometary Observations II. The Orbits of Comets III. The Structure and Composition of Comets IV. Where Comets Come From V. Recent Comets A. Comets of the Sixties and Seventies B. Comets of the Eighties and Nineties

SPC Spectroscopy, or "How Things Tell Us About Themselves by the Light They Produce" text pp. 22-27; 29-31; 217-221 (we’ll use some of this in the next unit)

I. Dispersion causes different wavelengths to be refracted through different angles. II. The Black Body Spectrum (Wien's Law) III. Spectral Lines A. The Absorption Spectrum B. The Emission Spectrum

SUN The Sun, or "Our Star" text pp. 201-211

I. The Interior of the Sun A. Energy Generation B. Structure II. The Visible Layers of the Sun A. The Photosphere (and Sunspots) B. The Chromosphere C. The Corona

SOL not included every semester

DIS Star Distance, or "How We Must Change Our Strategy When Studying Bodies for which We Cannot Discern Size or Shape" text pp. 221-223; 228-241 (some of this we’ll use in the next unit)

I. Measuring the Distances to Stars A. Trigonometric Parallax B. The Parsec and Light-year

STA Star Light, or "How Brightness, Luminosity, and Distance are Inexorably Linked"

35 text pp. 63-64; 223-225

I. The Inverse Square Law II. Magnitudes A. Apparent B. Absolute III. Star Colors

MAJOR CONCEPTS - UNIT III

Jupiter, the largest, most-massive planet in the Solar System, is an oblate sphere of mostly fluids. Only Saturn has a lower density.

The jovian planets are composed largely of hydrogen. The hydrogen may be gaseous, liquid, or (in the case of Jupiter) metallic.

The Galilean satellites are archetypal of a third class of planetary bodies that includes Pluto and the ring particles of Saturn: objects made largely of medium-density ice.

The surface of a planet or satellite tells the story of how much geologic activity it has experienced during its existence. Evi- dence includes crater density, texture, and variety of terrains.

Comets are icy bodies that orbit the Sun in very eccentric or bits. When they approach the Sun, their nuclei are heated so as to produce a gaseous coma and tail.

Spectra provide information about objects that produce light. A spectrum may be continuous, emission, or absorption, depending on the conditions under which it is produced.

The Sun illuminates and heats the Solar System. We see the Sun's photosphere; the chromosphere and corona are normally invisible to us.

In order to interpret the nature of things in the sky (such as stars), we must know their distance from us.

A star's apparent brightness is governed by its intrinsic luminosity and its distance from us. Only if one of these two quantities is known can we, based on the inverse square law of light, compute the other.

36 READING ASSIGNMENTS - UNIT IV

We see how stars change with time in this last unit. Following, we study groups of stars and the large-scale structure of the Universe.

HRD The H-R Diagram, or "How Stars Come in Varying Temperatures, Luminosities, and Sizes" text pp. 225-227

I. Stellar Spectra II. The Hertzsprung-Russell Diagram A. The Sizes of Stars B. Groupings on the H-R Diagram

LIV The Lives of Stars, or "How Stars, Like People, Are Born, Grow Up, Age, and Die" text pp. 247-257; 261

I. Star Formation II. The Main Sequence A. Energy Production B. Lifetime III. Giants and Supergiants A. Variables B. Energy Production IV. Mass Loss A. Planetary Nebulae B. Supernovae

DIE How Stars Die, or "How Many of those Exotic Objects in Science Fiction May Really Exist!" text pp. 262-278; 281-283; 285-290*

I. White Dwarfs II. Neutron Stars A. Spinning Up B. Pulsars III. Black Holes A. Characteristics of B. Detection of C. Effects of

WAY The Milky Way, or "How Everything We Have Talked About so Far Is distributed in Space" text pp. 293-298; 302-306; 309-310

*Warning: Your textbook authors love this topic. This is a particularly long reading assignment.

37 I. Groups of stars II. Motions of Stars A. Proper Motion B. Transverse and Radial Velocity C. The Doppler Principle D. Space Velocity III. The Galaxy A. Interpretation of the Milky Way B. Description of

GAL Other Galaxies, or "How Ours Is but One Ordinary Galaxy in a Vast Sea of Galaxies" text pp. 315-324

I. External Galaxies A. Properties of Galaxies B. Classifying Galaxies C. Galaxy Collisions II. Light Pollution III. Clusters of Galaxies

CML Cosmology, or "Why Our Place Can Never Be the Center of the Universe" text pp. 330-338; 365-370

I. Large-scale Structure of the Universe II. The Expanding Universe A. The Cosmological Redshift B. Quasars

CMG Cosmogony, or "How Our Universe Not Only Differs Greatly Over Tremendous Expanses of Space, But Also Over Tremendous Periods of Time" text pp. 370-377; 391-395; 399-402

I. The Big Bang A. Description of B. Consequences of C. Evidence for II. History of the Universe III. Vastness of the Universe in Time and Space

ETI The Search for Extraterrestrial Intelligence, or "Are We Alone?" text pp. 412-414; 417-430; 432

I. Where to Look II. The Greenbank Equation A. Star Production B. Planets C. Habitability D. Life

38 E. Intelligence F. Technology G. Survival III. Means of Communication A. Travel B. Radio IV. Consequences

MAJOR CONCEPTS - UNIT IV

The H-R diagram is a plot of luminosity (absolute magnitude) versus spectral class (temperature) for a sample of stars.

Stars spend most of their lives on the Main Sequence, fusing hydrogen into helium for power, with very little mass loss.

White dwarfs, neutron stars, and black holes represent end-states for stars of low, medium, and high final mass, respectively.

All the stars in the sky are moving. The general pattern is that of elliptical orbits about the center of our Galaxy.

Galaxies may be classified according to their appearance and to the age of the stars that comprise them.

The Big Bang theory attempts to explain the observed property of the Universe, that all objects in it seem to be receding from us and that the more distant an object is, the more rapidly it is receding, by invoking a universal expansion.

Two possible fates of the Universe await us: continued expansion and cooling ("heat death") or collapse into another primordial atom.

Contact with extraterrestrial intelligence, if such intelligence exists elsewhere in the Galaxy, is most likely to occur through the interception of radio signals rather than through space travel.

39 VOCABULARY

Here are some vocabulary terms you should be familiar with when preparing for your Exams. A study suggestion: Define each term to yourself, and then, to test your definitions, try putting each term into a sentence.

UUNNIITT II

Names

Eudoxus Nicholas Copernicus Tycho Brahe Johannes Kepler

Places

Sun Moon Universe Polaris Arctic Circle Antarctic Circle

Words star planet cosmology concentric spheres uniform circular motion geocentric heliocentric ellipse focus (of an ellipse) major axis / semimajor axis eccentricity Kepler's First Law Kepler's Second law perihelion aphelion constellation Celestial Sphere horizon altitude meridian Celestial Equator Celestial Hemispheres (North and South) Zenith nadir circumpolar Celestial Poles (North and South)

40 rotation revolution ecliptic precession obliquity Summer (Summer Solstice) Winter (Winter Solstice) Fall (Autumnal Equinox) Spring (Vernal or Spring Equinox) terminator sidereal month synodic month New Moon crescent Moon First Quarter Moon gibbous Moon Full Moon Third Quarter Moon waxing waning inferior planet inferior conjunction superior conjunction superior planet conjunction opposition total solar eclipse node partial solar eclipse annular eclipse total lunar eclipse partial lunar eclipse

41 UUNNIITT IIII

Names

Galileo Galilei Isaac Newton Mariner 10 Magellan Vikings 1 & 2

Places

Mercury Caloris Basin Venus Maxwell Montes Earth Luna (the Moon) Mars Olympus Mons Valles Marineris Ceres Phobos Deimos Barringer Crater

Words electromagnetic radiation wavelength Law of Reflection Law of Refraction convex lens focus (of a lens or mirror) objective eyepiece magnification focal length refracting telescope concave mirror reflecting telescope Kepler's Third Law period Astronomical Unit density terrestrial planet crater carbon dioxide runaway greenhouse effect resolution crust mantle core differentiation volcano

42 lava plate tectonics aurora nitrogen oxygen satellite lunar nearside lunar farside albedo highlands mare ray terraforming asteroid meteoroid meteor meteor shower meteorite micrometeoroid Tunguska Event

43 UUNNIITT IIIIII

Names

Voyager 1 & 2 William Herschel Clyde Tombaugh Christiaan Huygens Edmund Halley Jan Oort Giotto Wilhelm Wien Heinrich Schwabe Hipparchus

Places

Jupiter Great Red Spot Saturn Uranus Neptune Great Dark Spot Galilean Satellites Callisto Ganymede Europa Io Titan Pluto Oort Cloud Kuiper Belt Pleiades Sirius

Words hydrogen helium jovian planet metallic hydrogen zone belt ammonia barge white oval methane sulfur shepherd satellites spokes brown dwarf short period comet long period comet nucleus (of a comet) coma

44 tail solar wind dispersion infrared ultraviolet spectroscope black body Wien's Law continuous spectrum absorption spectrum emission spectrum core (of a star/the Sun) photosphere sunspot sunspot cycle chromosphere spicule corona prominence trigonometric parallax parsec light-year binary star visual binary Inverse-square Law luminosity apparent magnitude absolute magnitude

UUNNIITT IIVV

Names

Ejnar Hertzsprung Henry Russell Albert Einstein Christian Doppler Harlow Shapley Edwin Hubble

Places

Cygnus X-1 Milky Way Local Group Andromeda Galaxy ŠLarge Magellanic Cloud Small Magellanic Cloud Local Supercluster

Words

H-R Diagram main sequence giant branch nebula stellar evolution nuclear fusion electron proton neutron red giant variable star Cepheid variable iron planetary nebula supernova degenerate matter white dwarf neutronium neutron star pulsar black hole singularity escape velocity event horizon open cluster globular cluster proper motion transverse velocity radial velocity Doppler shift

46 disk (of a galaxy) halo (of a galaxy) spiral arm nucleus spiral galaxy barred spiral elliptical galaxy irregular galaxy light pollution cluster (of galaxies) cosmological redshift Hubble's Law quasar big bang cosmic background radiation primeval atom Greenbank equation SETI

A FEW WORDS ABOUT YOUR PROBLEM SETS

Your homework is not intended to help you prepare for exams. Instead, it is designed to expose you to some of the methods by which astronomers come up with something quantitative to say about the Universe.

The following five methods are suggested for helping you complete your problem-set homework assignments:

1. Attend class. Most (though not all) of the problems are directly related to mathematics presented in lecture. However, as most of the math occurs early in the course, you will have to look farther and farther back in your notes for subsequent home work assignment hints. Conversely, you will note that very little of the mathematics that you will need to complete homework problems can be found in the textbook.

2. Come by my office for help. I've even got my own blackboard!

3. Attend a help session. One of our upper-class earth-science majors sometimes agrees to offer homework help sessions in room LAT 113 (The Earth Science students' room). These are very informal. You can walk in any time between the posted session hours, and (s)he will give you a hand.

4. In the Reserve Section of the library is a binder containing old homework assignments from this course. The solutions have been worked out. Previous students have found them useful. You may checkout the binder for short-term use. Look at it or photo copy from it--just do not remove anything from the binder. The Reserve Section is straight ahead of you as you step off the main staircase into the basement. (Use is restricted to the library so that the binder will be available to all 870:010 students.) This material can be found on On-line Reserve, too; use HOCKEY as a password.

5. Be creative. I try to avoid "plug in the numbers"-type problems. Each one requires some imagination. Read them over. Play around with them. Draw pictures. Many are easier than they look . . .

Nevertheless, if you do poorly on an assignment, stop by so that we can look it over together. We may be able to develop a strategy by which you are able to do better on the next assignment.

48 HOW TO OBSERVE THE SUN

NOTE: It is very important that the filter be properly attached to the telescope before observing the Sun. Looking at the Sun through an unfiltered telescope, even briefly, may cause eye damage.

As you prepare to view the Sun, make sure you are looking straight through the eyepiece. (Try not to hold onto the telescope itself; you may accidentally move the telescope so that it is no longer pointing at the Sun.) You should see a circle of sky, surrounded by black at the periphery of your vision. This circle is called your "field of view." Inside the field of view will be the bright disk of the Sun. The Sun takes up most of the field. If it is not perfectly centered, one side of the Sun will be out of the field. This is fine as long as you can see most of the disk.

Look at the border between the solar disk and the sky. This is the limb of the Sun. It should appear sharp. If it is not, ask for help in focusing the telescope. It is easiest to use the telescope without eyeglasses. (You may bump the telescope with them and/or scratch them on the telescope.) Usually, the telescope can be focused to take the place of your glasses.

The Sun will appear brightest at the center of the disk. The disk will be smooth except for sunspots. You can recognize sunspots as small, dark, irregular patches on the solar disk. They are sharply defined and may consist of a very dark region, called the "umbra," surrounded by a slightly less dark region called the "penumbra." Remember that sunspots also tend to come in groups. These groups are most often short strings of spots consisting of one or two major spots and some less conspicuous ones.

You may notice some dust in your field of view, as well. In bright sunlight, every little speck shows up, and, therefor, it is impossible to keep the telescope completely clean for solar viewing. Do not confuse the dust spots for sunspots! Dust spots generally do not exhibit as much contrast as sunspots and are not as well focused. If you are unsure, the best test is to notice whether the spots move or not. (In time, you will be able to watch the Sun appear to move out of the field of view due to the rotation of the Earth; if it is breezy, the telescope itself may jiggle slightly.) Sunspots will move with the Sun, always re- maining in the same place on the solar disk. Because they are attached to the telescope and not the Sun, dust spots will always stay in the same place with respect to the field of view and not the solar disk.

Do not attempt to look for the sunspots with the naked eye. They are probably too small to resolve, and this practice is poten- tially dangerous to your eye.

"The Objects which astronomy discloses afford subjects of sublime contemplation, and tend to elevate the soul above vicious pas- sions and groveling pursuits." Thomas Dick (nineteenth century)