By Steven Ehrenberg
The stars are located in the Unicorn constellation, or pattern of stars, near Orion. (You can see Orion in the winter's night skyjust look for three bright stars close together in a line.) They're part of what scientists are calling the "Christmas Tree Cluster," a glowing cloud of space dust that looks a little like a holiday pine.
Stars form inside clusters. "We believe this process of forming stars in a cluster was exactly the same thing that happened with our own sun," said Erick T. Young, an astronomer at Arizona's Steward Observatory. "It tells us a lot about the history of our own solar system."
Astronomers estimate that our solar system is about 4 1/2 billion years old, while the Christmas Tree Cluster is "only" 1 to 3 billion years old.
Normally, the Christmas Tree Cluster looks like a haze of gas and dust. Astronomers peeked through the fog using the Spitzer Space Telescope, which is very sensitive to heat. Stars are much hotter than gas and dust, so the telescope captured the pink baby stars behind the cluster's blanket.
"That was a wonderful holiday surprise for us!" said Paula Teixera, the lead author of the study. She and her team plan to use the photograph to learn more about star birth.
The stars are 2,500 light years away from Earth. A light year is the distance traveled by light in one year—about 6 trillion miles.