Study Guide for Astronomy & Astrophysics I Exam 2 (Fall 2017)
Make sure you understand protostellar cloud collapse (Jeans radius and conditions for collapse, free-fall time for collapse, reason for and relation for increase of rotation and magnetic field)
- Understand the effects of interstellar reddening by dust, the differences in and reasons for colors of reflection and emission nebulae. Understand extinction and how to calculate distances of stars with and without extinction.
- Be familiar with tidal forces, how they arise, how they act on a body in both the external frame and the frame of the body.
- Be able to say what the selection effects are for the leading two extrasolar planet detection methods (radial velocity, or "wobble" method and the transit method). Understand what is measured in the radial velocity method, and why stars wobble.
- Review the reasons for the rapid advances in extrasolar planet discoveries.
- Know the observed characteristics of our solar system that any theory of planet formation have to account for. Be able to say how the current theory addresses these characteristics.
- Review the Hill radius, which gives the range of radii over which accretion through gravitational attraction is possible.
- Understand the Roche limit, and how to use the equation to calculate the minimum distance for bodies to approach a primary without tidal disruption.