# DAY 3

# Lecture Notes

#### Day 3 Intro Slides

Reminder of what we have done/some intro to what we are doing today.

# Code/Adventures

#### Some code that compares Hermite and Euler Integration Schemes with Analytical

Python code comparing different methods of integration for the 2-Body problem.

### Choose Your Own Adventure #1

#### CODE: Make a fake planetary system

Python code for solving for a multiplanet system.

** Questions: ** (1) How can you tell if the system is stable? (2) What effects stability?
(3) How hard is it to get a stable system? (4) What determines how long the computation takes?

### Choose Your Own Adventure #2

#### Make a planetary system based on Kepler data

Read in some Kepler data from a confirmed planet system and plot its orbits.

** Questions: ** (1) How can you tell if the system is stable? (2) What effects stability?
(3) How long does each system take to compute orbits? Why?

### Choose Your Own Adventure #3

#### Make a planetary system based on Kepler data - choose your own system

Learn more about how to access the Kepler database, format the data from your system of interest, and plot its orbits.

** Questions: ** (1) How can you tell if the system is stable? (2) What effects stability?
(3) How long does each system take to compute orbits? Why? (4) How do your systems compare to the
distribution of parameters of observed Kepler planetary systems? (5) How many Kepler systems do you think are stable?

### Choose Your Own Adventure #4

#### Calculate Orbits (and other 2-D things) with Rebound

Do calculations and plots with the python N-body solver "Rebound".

** Questions: ** (1) What do all the different integrators do? (2) Will some integrators be better for different sorts of systems?
(3) How can you test for stability in different N-Body systems?

# Resources

#### Indepth Discussion of Several Integrators

Goes over some pros/cons of different sorts of integrators. Hermite integrators are discussed in section 2.3.2.

#### Super Planet Crash!

Can you make a stable system?

#### Bonus: Orbits Game

Can you please your alien overlords by building them awesome planetary systems?