# Henyey track

The end (leftmost point) of every track is labeled with the star's mass in solar masses, and represents its position on the main sequence. The red curves labeled in years are isochrones at the given ages. In other words, stars ${\displaystyle 10^{5}}$ years old lie along the curve labeled ${\displaystyle 10^{5}}$, and similarly for the other 3 isochrones.