degeneracy pressure brown dwarf protostellar wind jet thermal pressure protostellar disk molecular cloud close binary 1. The Sun formed, probably along with other stars, within a large 2. A 3. A fusion reactions. consists of two stars that orbit each other every few days. is a "star" so small in mass that its core never gets hot enough to sustain nuclear 4. Most of the gas remaining from the process of star formation is swept into interstellar space by a 5. As a protostar's internal temperature increases, its growing due to gravity. 6. Planets may form within the 7. Mass can be lost through a that surrounds a forming star. helps slow its contraction of material ejected along a protostar's axis of rotation. 8. A "star" with mass below 0.08 solar mass has its gravitational contraction halted by