| INSTRUCTOR: | Dr. Derek Wills, Professor of Astronomy |
| Office: | RLM 17.204 |
| Phone: | 471-1392 |
| E-mail: | oo7@astro.as.utexas.edu |
| Office Hours: | MWF 2:00 - 3:00 p.m., or by appointment |
| TA: | Zhaohui Shang, Astronomy graduate student |
| Office: | RLM 16.220 |
| Phone: | 471-3447 |
| E-mail: | shang@astro.as.utexas.edu |
| Office Hours: | TTH 2:00 - 3:00 p.m., or by appointment |
| TEXTBOOK: | Astronomy Today, by Chaisson and McMillan (third edition) |
| GRADES: | There will be four in-class tests (9/18, 10/14, 11/11, and the last class day, 12/4), each counting 25% of the course grade. There is no final exam, or homework (but see below). There is no dropping of grades or extra work; this grading system is firm, as much for your sake as for mine. |
| TESTS: | These are based on material in the lectures, unless otherwise clearly stated, so study your notes when preparing for tests, rather than trying to memorize things from the book. Make-up tests will not be given unless there is a compelling reason presented in advance (or, of course, unless you are ill and cannot let me know in time). I shall hold a help session the night before each test - attendance is voluntary, but strongly recommended. |
| HOMEWORK: | There is no graded homework, but I will occasionally give out review questions on the material covered in class, and you will find it helpful to try these questions, partly to see how well you are understanding the material and partly because test questions will cover similar topics. For each set of questions, our TA will hold a help session before the keys are posted. While attendance is not required, you will find it helpful to go to these sessions if you can, and to try answering the questions before attending the review. |
| ABSENCES: | Because I am an observational astronomer, my research sometimes takes me to UT's McDonald Observatory in west Texas, or to other observatories. During my absence, the lectures will be given by another astronomy faculty member; his or her lectures are just as important as mine. |
| DROP DATES: | You can drop any course without academic penalty until Sep 23. You can then drop courses until Oct 21 with a Q or an F, depending on your performance in the class up to that time; I am lenient about Q's so long as you have been making an honest effort. If, for example, you fail both Test #1 and #2 (it can be done if you work at it!), I will still give Q drops if you have actually taken those tests. After Oct 21, it is harder to drop - you have to see your Dean and have a good non-academic reason; the Dean may consult me about your progress but he or she makes the final decision about whether you will be allowed to drop. This is also the last day to change between pass/fail and a letter grade (you can only take the course pass-fail if it's an elective, which is not the case for most of you). |
| STAR PARTIES: | Every Wednesday evening, there will be telescopes set up on the roof of RLM with graduate students to show you various astronomical sights. There is also a 9-inch telescope on Painter Hall that you can use if you are checked out on it, or attend public nights on Friday and Saturday evenings. |
| MATHEMATICS: | This is a science course, and you will have to do some mathematics, especially on the review problems. The tests will not include much mathematics, and in any case all the techniques you need will be demonstrated in class. AST 301, 302 or 303 is the only prerequisite for Ast 309R - common sense and clear thinking are more important than math wizardry! |
| COURSE OUTLINE: |
The official title of this course is "Time and the Cosmos", but it could equally well be called "Extremes in Astronomy" or "Gravity Usually Wins". We will look at extremes of age (the young Universe and its possible fates), density (black holes and the young Universe), rotation (pulsars) and luminosity and distance (quasars), and how the evolution of stars and the whole Universe is controlled by the relentless pull of gravity (in the case of the Universe, we are not yet sure whether gravity wins or not.....stay tuned).
We start with some essential background material, most of which you have probably covered in an earlier astronomy class - and some of which you may well have forgotten! We then look at the early days of radio astronomy, since radio astronomers have made many discoveries in the general area of cosmology, and we will be discussing these in the course. Radio astronomers were responsible for the discovery of both quasars and pulsars - very different types of object. We will only briefly cover the properties of quasars, and return to them in more detail toward the end of the course. Pulsars are believed to be neutron stars, and we will briefly discuss these, along with another possible end to a star's life - the black hole, massive versions of which are believed to fuel quasars. We then come to galaxies and cosmology - what we know or can deduce about the past and future of our universe. Finally, we return to the quasars and examine them in more detail, including their possible relevance to cosmology. There are many introductory astronomy textbooks that are suitable for the earlier course that you took here or elsewhere, and you may still have the textbook from that course. If so, you will find much of the background material in there to be useful in this course. However, there are unfortunately no suitable textbooks for the various versions of AST 309, including this one. The text I am recommending is one of the better AST 301/302-level books that goes into most topics in more detail than you did in your introductory course, and it should be helpful in most of the areas covered in this course. We will use basically the first and last quarters of it (missing out the solar system and normal stars). It doesn't go into quite the depth that we will do in this course, so you cannot rely on it instead of coming to the lectures. If you still have your earlier introductory textbook and want to use that instead, that will work, so long as you are familiar enough with it to find the various topics that we cover. In the following summary of the course, the numbers in parentheses are those chapters in Chaisson and McMillan that cover the various topics. But just because something is noted as being in e.g. Chapter 5 doesn't mean that you need to read everything in that chapter. Some topics are not covered in much depth in the textbook, so don't rely on it for last-minute panic studying the night before a test. With regular class attendance and a reasonable set of notes from the lectures you should have no problems. |
| Main Topics | Chapter |
|---|---|
| Background material: | |
| -scales and sizes in the Universe | 1 |
| -EM spectrum, wavelength and frequency, photons and waves, radiation laws | 3 |
| -spectral lines | 4 |
| -Doppler effect | 3 |
| -optical and radio telescopes | 5 |
| Radio Sources: | |
| -early radio astronomy | 5 |
| -synchrotron radiation | 25 |
| -discovery and properties of quasars | 25 |
| -pulsars, neutron stars and black holes | 22 |
| Cosmology: | |
| -galaxy types, distances and distributions, Hubble's law | 24 |
| -age of the Universe, evidence for the Big Bang, background radiation, cosmological models, open/closed Universes | 26, 27 |
| Quasars: | |
| -quasars and related objects - in more detail than above | 25 |