Astronomy 14 – Astrophysics: Solar System and Cosmology
Archive of Assignments
An optional and short Homework 7 [pdf] is due on Friday, May 11 by 5 pm.
Look over the slides shown in class on Thursday [pdf].
This is purely optional follow-up, but you might enjoy reading a paper by cosmologist Sean Carroll, Why is the Universe Accelerating? [pdf]. There are parts that will be hard to understand, but at least some of it should be comprehensible to each of you. It addresses cosmic coincidences, underlying physics we haven't discovered yet, and the role of the multiverse.
Read the assignment for Tuesday's class number 25 [pdf]. This includes a section of Ch. 19 about dark matter in spiral galaxies. Study the image below to see evidence for dark matter in our nearby neighbor, Andromeda.
Read this information about the upcoming midterm [pdf], which will be in class on Thursday, April 26.
Look over - and read - the slides I showed in class on Thursday [pdf].
Homework 6 [pdf] is due on Saturday, April 14 by 5 pm. Note that there are only four problems, but you're asked to read section 5.4 in the textbook in the context of one of the problems.
Read the assignment for Tuesday's class number 21 [pdf]. Part of that assignment is to read/study these slides on the cosmic microwave background (CMB) [pdf].
Look at the slides related to the cosmological principle [pdf] that were shown in Thursday's class.
Look over the slides of galaxy images, large-scale structure, and Hubble diagrams [pdf] shown in Tuesday's class, and read the assignment for Thursday's class 20 [pdf].
Take a look at my solutions to the KELT-1b problems we did in class last week [pdf] and also at my plot of exoplanets. The plot is only of exoplanets with known orbits (and masses and separations). Note that there are hot Jupiters (Jovian planets very close in to their host stars), warm Jupiters (more like Jupiter, but somewhat closer in), and then a bunch of super-earths and sub-neptunes found primarily by Kepler. Space-based light curves have less noise and so flux dips of less than one part in 10,000 can be measured from space. Hot Jupiters seem to have formed farther out and migrated inward (they don't have other planets in their systems). And we still have trouble finding low-mass planets with large separations (and long periods); presumably lots of them exist. The red star on the plot is the location and mass of the Earth.
Homework 5 [pdf] is due on Monday, April 2 by 7 pm.
For class 18 on Thursday, read carefully the four-page handout from the end of Tuesday's class [pdf], and answer the five questions on the last page. Bring your answers to class. You don't have to hand them in, but you should be prepared to go to the board and present your answer to any one of the questions.
Read the instructions for lab 4 [pdf] – email Ms. Klassen your observing proposal.
Take a look at one of the only directly imaged exoplanet systems, HR 8799.
Also, from last Thursday's class (16), take a look at the simulation of a gaseous sphere falling toward a more massive object, and being pulled apart as it crosses the Roche limit. And also the red giant star "overflowing its Roche lobe".
Read the assignment for Tuesday's class number 17 [pdf]. Note that there's something to hand in (via email) by Tuesday morning.
And take a look at the slides shown in Tuesday's class 15 [pdf].
Homework 4 [pdf] is due on Friday, March 23 by noon.
Read the assignment for Tuesday's class number 15 [pdf]. Note that we're calling this class 15 even though we didn't hold a class number 14.
There is no class this Thursday, but you can review the material from Tuesday's class (and the Ch. 10 reading) by looking over the slides shown in class 13 on Tuesday [pdf] as well as going over the questions on the in-class handout [pdf].
Read the manual for Lab 3 [pdf] before coming to lab meeting on Tuesday night. Put the data on your computer ahead of time, make sure you can open it up in AIJ, and do the reading preparation for the lab.
Read this information and set of topics [pdf] for the midterm.
Look over the images and graphs shown in Tuesday's class 9: the Maxwell-Boltzmann particle speed distribution, the cold proto-stellar cloud Barnard 68, young protostars with disks (proplyds) imaged in silhouette against a background nebula, ALMA radio telescope observations of the young star with a protoplanetary disk, HL Tauri, and beta Pictoris and its debris disk.
Homework 3 [pdf] is due on Saturday by 3 pm.
Look over the handout from class 8 [pdf], which shows two objects orbiting their common center of mass.
Homework 2 [pdf] is due on Friday by 5 pm.
Read the assignment for Thursday's class number 4 [pdf] – more light; new stuff is the inverse square law.
Read the assignment for Tuesday's class number 3 [pdf] – its focus is light (electromagnetic radiation).
Start on this short, first homework assignment [pdf] soon. It has only three problems, and it's due at the beginning of class on Tuesday. Note that at the beginning of the homework assignment, you're asked to read an online discussion about precision and also watch a short video about angular size. The links are here for your convenience.
Read the assignment for Thursday's class [pdf] – it involves solving the distance to and size of the Moon problems passed out in class on Tuesday (and now embedded in the assignment), and reading about parallax. You can also look at my hand-written version of the two problems [pdf] -- they include sketches, unlike the typeset versions in the assignment. Please bring your solutions to class, be ready to discuss them, and then hand them in.
Following up on our first class, practice measuring angles with your hands (see link to guide that was passed out at the end of the first class). And look over the slides from class that are posted below.
New: Look over the slides shown in the first class [pdf], which include student-chosen images from the first reading assignment.
Read the information Ms. Klassen sent about the first lab [pdf]. Read the first three pages of Ryden and Peterson Ch. 1 [pdf] before coming to lab. You should install AstroImageJ on your computer if you have the time and try loading an image of the Ring Nebula [zip].
Please read the assignment for the first class [pdf] carefully, and well ahead of our first class meeting on Tuesday afternoon. Part of the assignment is to watch Powers of Ten, a film about the scale of the universe, by Ray and Charles Eames. Here is a shared Google spreadsheet where you should sign up to claim a Solar System object, an image of which you will find and send to Prof. Cohen by midnight on Monday.
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This page is maintained by David Cohen
dcohen1 -at- swarthmore.edu
Last modified: May 11, 2018