Astronomy 16: Modern Astrophysics

Prof. David Cohen

Fall 2016
Tu., Th. 9:55 to 11:10
SC 113 (seminar room)


Eagle Nebula Sun in Halpha M 43 Andromeda





posted 7/26

Our first class meeting will be on Tuesday, August 30, in the seminar room in the Physics and Astronomy Department.

Our first lab meeting will be the following Tuesday, September 6, at 8 pm. We'll meet in SC 187 and then go up to the telescope. Update 8/24: We will try to have a lab meeting the second week of class, on September 6. So that you can have more interaction with the telescope controls during the first lab, I will split the class in half and some of you will use the telescope the next night, Wednesday, September 7. Update 8/28:Doing this is dependent on the weather and if it's quite cloudy, we'll have to postpone to the next week. We'll talk about this in class the first week.

I will be sending out a short assignment before the semester starts in order to get you prepared for our first class meeting. You'll get that about a week before classes start. Update 8/28: the assignment is posted below.

More information about the class (syllabus, etc.) will be posted on this site shortly.


posted 8/30

Please look over the reading assignment for class 2 [pdf], on Thursday. There is a small amount of reading in the textbook (on Kepler's laws), plus I ask you to look over these two short derivations of the expression for centripetal acceleration: [approximate but simple and more detailed and almost rigorous] and to make an orbit using the gravity simulator (which is permanently linked on the right side of this page). Also, please bring the in-class question from last time about the Moon's radius to class on Thursday and bring your print out of the finding-angles-with-your-hand guide, too. And come to class with questions.

posted 8/30

Today in our first class, students worked together to apply the distance-size-angle relationship to determine the size of the Moon [pdf]. And we did a little (indoor) practice measuring angles with our hands. We also looked at this Hubble Space Telescope image of the Carina Nebula and Star Formation Region and this image of a partial solar eclipse (with the Space Station). Note that these Astronomy Picture of the Day images have informative descriptions.

posted 8/28

The reading assignment for the first class [pdf] includes two problems that you must hand in by 6pm on Monday. Note that the reading is available on our class Moodle page (though just for this week; the book is available in the book store and at Cornell library).

Upcoming Events

Astro 16 students are members of the Department of Physics and Astronomy, and are encouraged to participate in department activities beyond the classroom. This includes attending regular talks – colloquia given by visiting scientists – and attending, and helping out with, the monthly telescope open houses at the Peter van de Kamp Observatory, on the roof of the Science Center.

Check the department colloquium schedule. The first colloquium of the semester – on Wednesday, September 21, will be given by an astrophysicist, Prof. Keivan Stassun (Vanderbilt), on the topic of new exoplanet discoveries expected from upcoming space telescope missions, Gaia and TESS.

The next observatory open house is on Tuesday, September 13 at 9 pm.


Class Information

David's office is SC 125 and his lab is SC 124, right across the hall.

Update 8/28: the syllabus, class information, and guidelines for reading and class will be posted here shortly.


Astronomy Picture of the Day

what's up in the sky this week

gravity simulator

Planet Crash

a Java-free orbit simulator

using your hands to measure angles

sky and weather information

observatory website

department website

class Moodle page



This page is maintained by David Cohen
cohen -at-

Last modified: August 30, 2016