University of Toledo professor leads breakthrough on stars

5/17/2010

This image from the Herschel Space Observatory shows a new star beginning to break out of a cloud of gas and dust. A Herschel image has led to new thinking among astronomers.

NOT BLADE PHOTO

A team of international astronomers led by a University of Toledo professor has made a surprising discovery that alters understanding of how stars are formed.

Their finding - a hole within the cloud of gas and dust that surrounds baby stars in the Orion constellation - turns a previous scientific assumption on its head.

Often referred to as "The Hunter," Orion contains one of the closest star-forming areas to Earth.

Since at least the 1970s, astronomers believed the hole in Orion was simply a very dense section of cloud, said UT associate professor Tom Megeath.

But using an image from the European Space Agency's Herschel Space Observatory - a powerful new infrared telescope - Mr. Megeath and his team realized the black space they saw had nothing in it.

"We got this image and we looked at it and we thought: 'Gosh, that's weird,'•" Mr. Megeath said. "•'What would cause a black shape like that?' It was just a striking feature."

After conducting additional observations on telescopes in Arizona and Chile, Mr. Megeath and his team concluded that the shape was, indeed, a hole.

The revelation is important because it helps unfurl a mystery about the "birth" of baby stars. Each star forms within a cloud, but scientists have been trying to understand how those "babies" eventually emerged. The new Herschel image shows the stars are clearing the cloud away by making a large hole in it, Mr. Megeath said.

The forming stars, or protostars, make the holes by throwing out jet streams of material, Mr. Megeath said.

"These holes are really starting to show this process in action," Mr. Megeath said. "We can now understand the process in a much more clear way than we have before."

Eventually, Mr. Megeath and his team hope to put together a detailed picture of the different stages of star for-

mation. He said that will help scientists understand how our own sun, and the planets, came about.

There will be plenty more material to work with. The current discovery emerged from just one hour of observation, and the team has permission to use the telescope for 200 more hours. That data should be made available at the end of the summer.

"When you have a new telescope unlike anything that we've had before, even with just an hour of time you can do something unprecedented, revolutionary," Mr. Megeath said. "I am really excited about this."

Mr. Megeath arrived at UT in 2006 from the Harvard Smithsonian Center for Astrophysics.

Karen Bjorkman, chairman of the UT Department of Physics and Astronomy, said Mr. Megeath's work is bringing new attention to the university. She said she hopes this latest discovery will bring more experts and students to Toledo. "It's just great to have his expertise here," Ms. Bjorkman said. "It really makes the University of Toledo into a sort of center for a lot of this work on how stars form."

Contact Claudia Boyd-Barrett at:

cbarrett@theblade.com

or 419-724-6272.