Making Stars

The hot stars at the center of a nearby nursery may have Jekyll and Hyde personalities. On the one hand, they appear to trigger the birth of new stars. On the other, they may prevent the birth of even more.

Cepheus OB4 is a giant complex of gas, dust, young stars, and newly forming stars. It’s about 3600 light-years away, along the border between Cepheus and Cassiopeia, which are in the northeast at nightfall.

The name of the complex indicates that it contains many class O and B stars. They’re especially hot, bright, and heavy. OB regions are where most stars are born, so they’re great labs for studying the birth of all stars.

O and B stars produce powerful “winds” of hot gas. The winds ram into the surrounding clouds of gas and dust. That can cause the clouds to collapse and form new stars. But it can also blow away the material for new stars, shutting down starbirth.

And a recent study says that both processes appear to be at work in Cepheus OB4.

Researchers looked at about 760 young stellar objects — either infant stars or dense blobs that are about to become stars. They found many of them in regions with dense clumps of gas and dust. But they found few of them outside those regions. So winds from the stars at the center of the complex may be triggering starbirth in some places, but clearing out regions where the raw materials are more thinly spread — blocking the birth of even more stars.

More tomorrow.
 

Script by Damond Benningfield