Astronomy 16 – Astrophysics: Stars, ISM, and Galaxies

Prof. David Cohen

Fall 2018
Tu., Th. 11:20 to 12:35
SC 113 (seminar room)


spectral types M 43 Andromeda





posted 12/10

Our last class is on Tuesday!

There is a new homework assignment, with three relatively short problems, due on Friday. See below.

Information about the final (Dec 20, in the morning) will be posted below, shortly.

Archive of old announcements


posted 12/10

Homework #10 [pdf] is due on Friday, December 14 by 6pm. There are three problems on it.

posted 12/7

The assignment for class 26 [pdf]: our last class meeting. We'll discuss the distance ladder and the evidence for the expansion of the universe and the big bang.

Hubble Deep Field

Take a look at the slides from Thursday's class [pdf], with images of other galaxies, interacting galaxies, galaxy clusters with gravitational lensing...

Archive of old assignments

Upcoming Events

What's up in the sky this week - the sky is always changing: keep an eye on the bright objects that are up in the sky each night.

The department has regular talks – colloquia – given by visiting scientists. Check the department colloquium schedule to see the list of talks. You'll find titles and descriptions of the talks, which are generally on Fridays at lunchtime. We will have four or five this semester, with at least one on astrophysics.


Class Information

Prof. Cohen's office hours will generally be: Wednesday from 3:00 to 4:30, Thursday from 1:30 to 3:00 and Friday from 3:30 to 4:30; weekly deviations from this schedule will be posted here.
This week (12/10-14): I have to cancel office hours on Thursday, I'm afraid. Get in touch by email if you want to schedule a meeting and can't make it to Wed or Fri office hours.

Katie and Graham, our SAs, will hold a weekly SA session on Thursday nights, from 7 to 9 pm, in L32.

Prof. Cohen's office is SC 125 and his lab is SC 124, right across the hall; Prof. Jensen's office is next door, in SC 123. Prof. Jensen is the lab instructor; we'll be having lab meetings on (some) Tuesday nights throughout the semester.

A syllabus [pdf] with information about the class as well as a schedule of topics, reading, labs, and exams is available – note that it will be periodically updated – updated November 23.

Please also read these guidelines about the class [pdf], including rules for the classroom but also information about the growth mindset and about equity and inclusion


Astronomy Picture of the Day

Messier Monday blog


AstroImageJ (AIJ) telescope data analysis software

Tapir observation planner


gravity simulator

a Java-free orbit simulator


using your hands to measure angles


observatory website

department website



This page is maintained by David Cohen
dcohen1 -at-

Last modified: December 7, 2018