Astronomy 1: Introductory Astronomy

Prof. David Cohen

Spring 2014
Tu., Th. 9:55 to 11:10
SC 128


Saturn Butterfly Nebula Abel 68


Click on each image for more information about these objects.



updated Apr. 10

Our second midterm is on Tuesday, in class. Information will be posted below, in the Assignments section by the end of the night, tonight.

There will be an SA session on Sunday night in SC 105 from 7:00 to 9:00 pm. But David will be out of town on Friday and Monday, and so will not be able to hold office hours. Get in touch with questions by email anytime, though. Homework solutions will be posted over the weekend.

We'll be learning about galaxies, and specifically, the Milky Way galaxy, starting next Thursday. You can start reading Ch. 19 to prepare, but you certainly don't have to before Tuesday's exam.

Our final lab meeting will be this coming week. The Monday and Tuesday sections will do the Expansion of the Universe lab, but the Wednesday and Thursday sections will be attempting to make up the second observing lab.

Archive of old announcements.


updated Apr. 12

The Monday and Tuesday lab sections will be doing the Expansion of the Universe lab. Please look over the manual carefully, especially as this is material we have not yet covered in class. For the Wednesday and Thursday night sections, you'll be trying to make up the second observing lab. Read that manual ahead of time, as there are quite a few different observations you'll be making, and you'll be comparing some of them to observations you made in the first observing lab.

updated Apr. 11

The exam will be on all the material since the first midterm: the Solar System, Exoplanets, Telescopes, and the historical development of astronomy. Here is the equation sheet you'll be given in the exam. Updated on Apr. 13.

Look at this gif of Venus cycling through its phases. Can you identify the phases that show that the Ptolemaic system is wrong? And can you explain why Venus looks bigger at certain phases?

updated Apr. 10

Review the slides from Tuesday's class (plus the separate set, showing the retrograde motion animations) and the slides from Thursday's class.

updated Apr. 4

When you have a chance, take a look at these articles announcing the discovery of a liquid water ocean on one of Saturn's moons and evidence for organic molecules (careful, not biological molecules) in it: New York Times and a short and slightly more technical (but not overly so) article from Nature.

Archive of old assignments.

Upcoming Events

There are telescope public viewings the second Tuesday of each month, at the Peter van de Kamp Observatory on the roof of the Science Center. The next one is on May 13, at 9 PM. Come on by, and bring a friend who isn't taking astronomy. The Moon and Jupiter will both be visible then, and Saturn may also be above the tree-line.


Class Information

Information about the class [pdf]

Guidelines for the class [pdf]

This syllabus will be updated periodically (new version posted Apr. 4).

office hours


Astronomy Picture of the Day

what's up in the sky this week

sky and weather information

Stellarium software

Powers of Ten

PhET orbit simulator

department website



This page is maintained by David Cohen
cohen -at-

Last modified: April 12, 2014