How is the H-R diagram utilized to determine the age of stars in a globular cluster?

Answer

By identifying the 'turn-off point' on the Main Sequence

The 'turn-off point' indicates the mass of stars that are currently exhausting their hydrogen fuel, which sets the age for the entire cluster population formed simultaneously.

How is the H-R diagram utilized to determine the age of stars in a globular cluster?

#Videos

HR Diagram Explained - Star Color, Temperature and Luminosity

temperaturesequencestarLuminositydiagram