Multiple Choice
What must occur for an object to be considered a main-sequence star?
A) hydrostatic equilibrium
B) nuclear fusion reaction in the core
C) protostar life begins
D) both a and b
Correct Answer:

Verified
Correct Answer:
Verified
Related Questions
Q4: How does a gas cloud become hot
Q15: What observations reveal star formation in the
Q45: _ are small dark nebulae about 1
Q70: The hottest stars in the Orion Nebula
Q72: Why do nuclear fusion reactions only take
Q77: Which of the following is NOT evidence
Q88: Opacity is<br>A)the balance between the pressure and
Q95: As a star begin to form the
Q98: The Orion region contains young main-sequence stars
Q108: HII regions are found near stars cooler