You observe a star cluster with a main-sequence turn-off point at spectral type G2 (the same 36) spectral type as the Sun). What is the age of this star cluster?
A) 4.6 billion years
B) 10 billion years
C) 100 billion years
D) 10,000 years
E) You also need to know the luminosity class of the turn-off point to determine the age.
