This page is designed to collect tips and hints from grad students who have passed their prelims. Clearly everyone's prelim scenario is different, but there are always some similarities. Hopefully some of the advice below will make your study time minimally painful and maximally excellent!

Chat Hull

Greetings! Chat here.

I took my prelim in February of 2010. My topics were Radiation (Geoff Bower), Galaxies (Leo Blitz), and Star Formation (Steve Stahler).

Here I'll outline my general study method in hopes that it might be of use to future generations of grad students who might otherwise spend too much time destroying their bodies and souls unnecessarily.

A couple of notes regarding my situation:

  • I purposefully took both Galaxies and Star Formation the semester before my prelim, so much of the material was fresh in my mind. I realize that's not a possibility for everyone, because course offerings different from semester to semester; however, one should strive to leave as little time as possible between completion of prelim courses and the prelim itself.
  • While I didn't work as hard in Radiation as I probably should have, I wised up during my second year. When I decided that Galaxies and Star Formation were going to be my other two topics, I worked very hard in both of them for the entire semester. In particular, I found reading the textbooks to be helpful. It takes a lot of time, but it really gives you a better mental picture of the course than just sitting in lecture for three hours a week and doing bi-monthly problem sets.
  • The first step in my outline below involves outlining your class notes. This is something of an arduous (but necessary!) process, and can take several days per course. Therefore, if you have the time to outline your notes as you prepare for each class's end-of-semester exam, it's well worth it. That way when your prelim rolls around you can use your previously distilled notes for those classes. In my case, I had distilled packets from Radiation and Galaxies, since I had oral exams in both. I had to create a distilled packet for Star Formation.
  • I left myself just under a month. If you need to make packets for all three courses, I might leave a little over a month, but not too much more.
  • Finally, I found that practicing at a chalkboard with another student was quite possibly the most useful part of the process. This may not be possible for you, but if you manage to coordinate both the prelim dates (close together) and prelim topics (similar courses) with another student, you won't be sorry you did!

Outline notes (weeks 1 and 2)

  • If you haven't already outlined your notes for an exam, this is a good place to start. I take a lot of notes, so I had ~140 pages of notes for each class. I was generally able to distill those 140 pages into 40-60 pages of compressed notes. It's usually easy to cut out things that you know won't be on the prelim: derivations that took the entire class, topics that even the professor hadn't the slightest clue about, etc.
  • The distillation process should take 3-4 days per class, with 4-5 hours of work per day.
  • I like to use un-lined paper. It looks nice and lets you draw pictures.

Make a topic list

  • Once you have your packet of compressed notes, go through them and the book and make a list of general topics and specific subtopics that you need to be familiar with. Depending on how detailed you get, this should be anywhere from 2-4 pages.
  • This should serve as a check on your brain to make sure that you're beginning to see the big picture of the course. Making a topic list should be relatively quick and painless, because after you've distilled your notes you should find that your brain is clarifying which topics are the most central to the class.

Make note cards (week 3)

  • Once you've distilled your notes and then zoomed out and made your topic list, you're ready to start making note cards.
  • I went to Staples and bought four different colors of note cards, a different color for each class, and white for my stack of “fundamental” cards.
  • First things first: make your stack of fundamental cards! c, k, e, G, h, Jy, eV, solar mass…they should all be on there! If you start memorizing early, you'll have all of the numbers down by week three.
  • Once you've done that, start making a stack of cards for each class. Each card should include an even more distilled chunk of information about a particular topic. For example, you might have one note card that briefly outlines the steps in the synchrotron power derivation. Another might have the equation for the Jeans Mass. Another might attempt to explain the difference between TE and LTE. You get the idea.
  • You should strive to be finished with your note cards several days before your practice prelim, just under three weeks into your studying.

Study with other people! (weeks 3 & 4)

  • Once you've gotten into note card phase, it's time to start practicing with other people who might be taken their prelim near the same time that you'll be taking yours. THIS KIND OF PRACTICE IS INVALUABLE! Have the person/people quiz you on past prelim questions, or simply as you questions out of the book. While this helps you to clarify your understanding of particular topics, it also allows you to practice presenting prelim-style: you need to explain concepts well, you need to have clear board work, and you need to learn to deal with the feeling of not knowing the answer right off the bat. Once you've worked for several hours with someone, those skills will start to come more naturally. This will help you immensely during your prelim.
  • Ideally you should be able to study with someone several times before your practice prelim. Your practice prelim will help you hone your presentation skills, but won't be as helpful when it comes to concept clarification.

General tips (i.e. "How to keep your brain fresh")

  • Spend no more than 3 days at a time on any given class. I found that cycling through my classes helped to keep my brain fresh…once I started getting bored of one topic, it was time to switch to another one.
  • Don't study for more than 5 hours a day. Most days I studied 3-4 hours. More than that and your brain starts to turn off. 1 hour of productive, focused study time is worth more than 4 of wishy-washy, pseudo-focused time! That doesn't mean you can check your email, but it means that when you're studying, you should really be burning your brain cells. If you can only stand it for 45 minutes, fine. But make sure that you're really focusing during that time. Then go take a break.
  • Review your flash cards before bed. I found that flipping through one stack of flash cards before I went to bed helped me to remember the stuff better. Granted, sometimes I'd dream about it, which wasn't fun, but hey…whatever it takes to get it in there!
  • Don't put too much stock in past prelim questions. They're useful to study from, and you should know the answers to all of the questions, but expect that most of the questions you get will be different from the past prelims.
  • Change your study venue. I liked to cycle among different places, especially new places, since they didn't have any familiar distractions. Cafés are good. Libraries are good. I even studied for a few hours at Fat Apples.
  • Use a white board. Practicing derivations on a white board helped me memorize them much better than writing them on paper or reading about them on the back of my note cards.
  • Take at least one full day off per week. And I mean a FULL DAY. Don't think about studying. Put your books in the trunk of your car if you have to. Go on a hike. Watch football. But DON'T STUDY. Your brain needs that kind of refreshing.
  • Don't totally destroy your social life! Go to a party on the weekend. Go out for a beer some night after you've finished studying. Interaction with cool people is just as much of a refresher as going to the gym or switching up which class you're studying for.
  • Exercise at least twice a week. I went to the gym more when I was studying than I did during any previous semester, and it paid off. If you don't get a release from exercise on a regular basis, your sympathetic nervous system will start to destroy you with the low-level stress that you feel while you're studying. That leads to great inefficiency.
  • Eat a good diet. Seriously. You need your body to work.
  • Do everything in moderation, and with regularity. Look over your stacks of note cards at regular intervals. Don't focus for too long on one class. Take regular breaks. Study regularly with someone. Doing ten 15-hour days of just Star Formation isn't gonna do the trick. Moderation is key.

That's about it. I didn't end up spouting as many memorized quantities or definitions as I thought I would; however, I still think the exercise of making the distilled notes and the note cards was useful, especially when combined with lots of good face-time with another student in a stand-up, prelim-style situation. In the end, preparing using the above tactics enabled me to dig myself out of a lot of holes during my prelim, even if I hadn't studied in-depth the exact topic that they were quizzing me on. Why exactly my method worked, I can't really say, but I hope it works for you, too!

Aaron Lee

If you became exhausted just looking at the length of Chat Hull's comments above, you are not alone. However, my first piece of advice is to eventually read through Chat's treatise on prelim studying. While I do not agree with all of it (we all have different study habits), he gives a lot of good “obvious” advice. Obvious in that it seems, well, obvious, but is still good to read and remind yourself of.

I took my prelim in early September 2010. My prelim topics were Stellar Interiors (Quataert), ISM (Heiles), and Fluids (Stahler). I sat in on Quataert's class in Fall 2008, took ISM in Spring 2010, and took Fluids in Spring 2009. My practice prelim was ~two weeks before my actual exam.

My background situation:

  • I spent 1.5 months preparing. During this study period I was also writing up papers for submission to ApJ, which is why I wanted more than the typically quoted 1 month of study time. The ApJ writing was a good distraction from studying, giving my brain some time to relax. I would not recommend locking yourself in a room and studying nonstop. On a similar note, I wish I would have exercised more during the summer. Exercise is a refreshing break that stimulates brain activity, and it should not be dismissed from your schedule while preparing.

My emotional state:

  • I went into studying with a positive attitude. I had this grand plan that I would study for a vast number of hours each day, memorizing numbers and derivations and explanations the descended all the way to first principles. I acquired all the “recommended” and “optional” textbooks and was prepared to peruse them all. After about a week of doing this, I fell into a depressed state and was convinced all hope was lost. I started looking at applications for community college math teachers back home in Michigan, hoping to use my applied math degree from England as my credential. The song “Midnight Train to Georgia” became stuck in my head for most of August (possibly not related, though I'll argue it is). I developed a twitch in my right eye. My sleep schedule rotated so that I was sleeping until 2pm each day and staying up until 6am. Then in the last three weeks or so, it got better. As more of the material became ingrained in my memory, my self confidence started to return. Once game day came, I was so sick of studying that I no longer cared about the results. I just wanted to get it over with.
  • Why am I telling you this? Here's my takeaway: Go in positively, but don't try to learn everything (see Chat's comments on this). There will be dark times, but push through them and the light will come. Be persistent: if you get to the point where you are sick of studying, that is not necessarily a bad thing. But don't slack off!

Study schedule and habits:

  • I bought a hardcover notebook from Staples for each subject. I bought a nice set of colored pens and a pack of my favorite black pens. Taking one subject at a time, I re-copied all my lecture notes into the books, fleshing out details, filling in blanks of derivations, and highlighting important concepts. If quoted numbers had a quick order of magnitude derivation, I sketched it out in the book. Each book had a table of contents. At the end of the lecture notes, I hand-wrote answers to the previous prelim questions. If I did additional questions from textbooks, I wrote out their solutions in these books as well.
  • Notecards do not work for me. I only had them for memorizing numbers, not concepts. For concepts, I tested myself by trying to reproduce derivations and physical arguments on my dry erase board in my bedroom.
  • I either worked in my bedroom or at Berkeley Espresso.
  • I took at least one day off a week. I felt guilty for doing it at first, but am glad I did. The brain must rest.
  • I did not study with other people. However, I think you should consider it if others are also studying for prelims at the same time. Practice writing on the board. The practice prelim was very useful, as well.
  • The night before the exam, I watched a movie. I did not study beyond glancing over my notes.


  • Also memorize relevant timescales, lengths, etc. for whatever subject you are studying. For example, to order of magnitude, what are the timescales for the various parts of a star's life (pre-MS, MS, Red Giant, etc.)? What sets these timescales?
  • SOLVE PROBLEMS! Redo your problem sets (or, as in my case for Stellar Interiors, DO the problem sets if you haven't already). Complete additional questions at the end of chapters. Go back to Carroll and Ostlie and complete all the “elementary” problems on the relevant topics.
  • My adviser told me that since I was interested in doing theory and not observation, my prelim would be “harder.” People told me not to believe him, but there is some truth to what he said. I had fewer questions of me just spurting out numbers or talking about how we observe certain things, but rather was asked to do quick derivations and justify concepts using physical reasoning (e.g., compare my questions from Heiles to other Heiles ISM prelims). Look at McCourt's, Shiode's, and my questions in comparison to Hull's or Viscomi's. There are (sometimes subtle) differences in the types of questions. Am I saying observers have it easy? Of course not. Carl did ask me an observation question, which to an observer would have probably been an easy question. But I initially got it wrong (though figured it out eventually). Just keep in mind that your interests “may” affect what you are asked.

Casey Lam

Seems like nobody's added anything to this page in a while, so figured I'd throw in my two cents. I took my prelim in early January 2019. Subjects were Fluids (Chung-Pei Ma), Galaxies (Mariska Kriek), and High Energy (Josh Bloom). I had taken High Energy the semester before (Fall 2018), and Fluids and Galaxies the semester before that (Spring 2018).


  • High Energy had a final exam so I spent a decent amount of time (around a week) studying for that, two weeks before my “official” prelim studying began.
  • I spent a month preparing, beginning after finals week was over. Studying through winter break has it's pros and cons (obvious con: you spend your winter break studying. Pros: it's nicer to study at home (in my opinion), and if you take a prelim in a fall class, you'll already have studied a bunch for that.)
  • I studied every day, although sometimes it was pretty minimal, like an hour or two of reading the textbook. It helped for me to constantly have the material “stew” in my mind to keep the momentum going.
  • I took a practice prelim a week before the actual prelim– definitely very helpful!


  • Practice your boardwork, and maybe even more importantly, explaining your boardwork out loud. It's easier to write on paper or flip through flashcards and answer things in your mind, but actually getting up in front of the board is invaluable practice.
  • The oral final exams for classes are pretty representative of the prelim, and are also great practice.
  • Take your prelim as soon as possible. That way, you get it out of the way (prelim studying is pretty interruptive to your research/life in general), and the material is fresh in your mind.
  • That being said, if you don't have an astronomy background from college, there's no problem in waiting longer to take your prelim. I had taken enough classes by Spring 2018 to do a prelim, and could have taken it that summer (which several of my classmates did), but I didn't feel ready. I found that GSI-ing for undergrad classes, in particular Astro 7A and 7B, to be incredibly helpful in understanding the “culture” of astrophysics and getting the basics down. It really helped put the things from grad classes into perspective/context.