Class 5- Solar System Formation - Nebula Collapse

Reading - Chapter 4 of Hartmann (plus Chapter 2 of The New Solar System - optional)

What are the characteristics of the solar system that a theory of formation need to explain? Short version - extended version. An important characteristic is the angular momentum distribution in the solar system. Current theories are barely beyond the level of a sketch. What about other solar systems? Clearly, the ones detected so far are rather different from ours - we need to keep this in mind and consider the differences as we develop a theory.

This class is an excuse to look at some neat pictures of nebulae! These are from the HST site.
Orion nebula - large scale picture of the orion nebula - a local star-forming region of the Galaxy
Orion closeup - look for the small, nascent solar systems
Proplyds - and another - PROtoPLanetarYDisks - about the size of our solar system
Tryfid nebula - another neat one - smaller version
M16 - not the gun - the famous nebula - The Movie
Pleiades - Evaporation of molecular cloud by nearby stars

Disks - overview

Collapse of molecular clouds - Virial theorem, minimum mass / density - see Figure 4-3

Conservation of angular momentum - where did the original angular momentum come from? Think of a bathtub or the experiment /demo in class - many small eddies mostly cancel out but eventually add up to some net angular momentum (in random orientation). As the cloud collapses (or water pours down the drain) the angular momentum is conserved and the fluid spins up.