1. Density Waves and Migrating Planets 3 December 2014

2. Star forming region in Giant Molecular Clouds

3. Proto- Planetar disks

4. Hubble Views of Proplyds

5. Comet and asteroid collisions

7. Propeller Structures

8. Protoplanets form, opening gaps

9. Inside the nebula

11. Propellers Again!

12. Summary Protoplanets in the protoplanetary disk resemble moons embedded in rings They open gaps and raise density waves Type 1 migration: waves transport momentum: as the planet loses momentum, it spirals in Type 2 migration: a gap forms and the moon is dragged in along with the disk When the star turns on, it blows away the disk, leaving the planet behind as a ‘hot Jupiter’