- *What controls the mass-energy-chemical cycles within galaxies?
*What are the connections between dark and luminous matter?
*How do baryons cycle in and out of galaxies, and what do they do while they are there?
*How do black holes grow, radiate, and influence their surroundings?
*How do stars form?
*How do circumstellar disks evolve and form planetary systems?
*How do rotation and magnetic fields affect stars?
*What are the progenitors of Type 1a supernovae and how do they explode?
*How do the lives of massive stars end?
*What controls the mass, radius, and spin of compact stellar remnants?