What mechanism causes young stars to rotate much faster than older stars of the same mass?
Answer
Magnetic braking, which sweeps stellar wind particles out into space.
Magnetic braking acts like a brake over billions of years; the star's magnetic field carries away stellar wind particles, which removes angular momentum and slows the star's spin rate.

#Videos
How Do We Measure the Ages of Stars? With Astrophysicist Ruth ...
Related Questions
What single factor overwhelmingly dictates the life cycle and lifespan of a star?What is the primary phase where stars spend the vast majority of their active lives fusing hydrogen in their core?In cluster dating, what feature on the Hertzsprung-Russell diagram determines the age of the entire group?If an isolated G-type star shows a noticeable depletion of Lithium in its spectrum, what does this suggest about its age?What mechanism causes young stars to rotate much faster than older stars of the same mass?Asteroseismology estimates stellar age by monitoring what phenomenon?What are the two parameters plotted against each other on the Hertzsprung-Russell (H-R) diagram?Why is dating a large group of stars in a cluster generally more reliable than dating an isolated field star?According to the text, how long is the Sun's estimated total main-sequence lifespan?What causes the primary difficulty when estimating the age of an individual, solitary star?