Spinning Stars

The beautiful Pleiades is high in the west as night falls at this time of year. The star cluster looks like a tiny dipper. Right now, it stands above bright orange Mars by about the width of your fist held at arm's length.

The cluster contains hundreds of stars. All of them were born at the same time, from the same cloud of gas and dust. That makes the Pleiades a great laboratory for studying how stars evolve. Since all of the stars were born from the same raw materials, any differences are the result of the evolution of the stars themselves.

Astronomers can also examine the individual stars to learn about the overall cluster.

One recent study, for example, looked at how the stars of the Pleiades rotate. The results can provide insights into conditions when the stars were born.

Researchers looked at observations of the cluster from two space telescopes and one ground-based telescope, then performed a statistical analysis.

There are a couple of models that predict how stars in a cluster should rotate. One says that the stars should inherit their rotation from the spin of the cloud that gave them birth. But the other says that conditions in a cluster are turbulent. That jumbles up the stars and makes them spin in different directions.

The study suggests that the stars of the Pleiades rotate randomly — every star spins in its own way. That supports the second idea — providing a new view into the birth of a star cluster.

Script by Damond Benningfield