Astronomers Studying Stellar Evolution Draw a Curve on a Hertzsprung-Russell

question 202

Multiple Choice

Astronomers studying stellar evolution draw a curve on a Hertzsprung-Russell diagram called a "birth line". What does the birth line represent?

• A) evolutionary track of a 1-solar-mass star (i.e., the Sun)
• B) coordinates of the initial collapse of dense cores of various initial masses
• C) coordinates of the transformation of protostars of various masses into pre-main-sequence stars
• D) coordinates of the transformation of pre-main-sequence stars of various masses into main-sequence stars