1. Clearly explain the difference between a reflection and an emission nebula, in terms of
the physical conditions that you would notice and experience inside of one, and the
differences you would see in them when observed in an earth-based telescope.
2. Describe the conditions that are necessary to form an emission nebula, and how these
conditions produce the nebula.
3. The Sun is surrounded by interstellar hydrogen gas. Why doesn’t the Sun create an
emission nebula?
4. Why are emission nebulae popular locations for star formation?
5. Describe the way a 1 solar mass cloud of gas and dust changes as it collapses to become
a star. Explain the key features of the protostellar nebula’s track through the HR
diagram.
6. Discuss brown dwarfs. Why are they created? How well have they been studied?
How common are they?
7. Describe at least two features that we can find in telescope images of emission nebulae
that show the last stages of a star’s “birth” and entry onto the Main Sequence.
8. What happens during the T Tauri phase? At what point in a star’s development does this
occur?
