Hometown U: UAA astronomer discovers star births

Hometown UJanuary 19, 2013 

UAA astronomer Travis Rector recently stumbled upon the birth of some stars out near the Big Dipper.

That sounds like a big deal.

"To be perfectly honest," he wrote in an email, "it's not a major result, but it's a neat discovery and it has a beautiful picture to go with it."

Since when is the birth of baby stars -- or Young Star Objects (YSOs in astronomy-speak) -- not news? It certainly had my Monday beat by a long shot.

I joined him in front of a computer to look at the starlets and find out how he'd discovered them.

The image we looked at was originally captured in 2009 through a telescope at Kitt Peak in Arizona. The scene it captured was ethereal -- smoky and blue, with a fierce bright light emanating from the center. Toward the outer edges, star points pricked the deep, empty black. Beautiful, and otherworldly.

Officially, this is NGC 7023. Informally, it's the Iris Nebula, so named for its violet and blue color and flower shape. Nebula is Latin for cloud, and in this case it's a cluster of dust, hydrogen, helium and other gases that can clump together and give birth to stars.

But this beautiful image is not what the telescope saw, Rector said.

He pulled up the raw file -- exactly what the telescope did see. It included eight rectangular black-and-white snapshots of the sky, pieced together to create the full image -- a dull, gray version of the Iris Nebula.

The telescope doesn't see color, he explained. It simply measures the intensity of light. While the Iris Nebula is as big as our moon, it's very, very faint.

"If you were standing right next to it, you wouldn't see it," he said.

That's because the iris of the human eye is just a few millimeters across and takes short exposures very fast. It could never capture such faint light.

The iris for the camera that took the images, on the other hand, is four meters across, or about the size of Rector's UAA office. Exposures take about an hour per filter. The filters -- red, green and blue -- colorize the faint light and allow the human eye to see it.

So the observatory had emailed him the raw data file of NGC 7023 and asked him to produce an image the human eye could see. It was a nothing-special file, just a chance for another awe-inspiring picture from space.

Rector has a national reputation for creating these. Back in 1997, when he was working at the Kitt Peak National Observatory, the Hubble Space Telescope was getting lots of attention for releasing a monthly image from space.

A new camera on one of Kitt Peak's telescopes had a field of view about 1,000 times bigger than Hubble's, so astronomers there wanted to try making some color images as well.

Rector got the assignment.

"It's something I thought I'd do once," he said, "and I've been doing it ever since."

Observatories like creating and sharing these impressive images, so taxpayers know what such pricey, publicly owned telescopes are up to.

Rector converted NGC 7023's raw data to something he could load into Photoshop and applied filters to make faint light visible.

His unique contribution was this: Just for fun, after he'd applied green and blue filters, he tried a "hydrogen alpha filter" capable of detecting red light. And that's when -- through an infrared telescope -- he saw the small, reddish cloud patches associated with star births.

Rector picked them out in the image and started researching to see if they'd been spotted before. Experts confirmed they had not.

The thrill for Rector was making a discovery in an area he doesn't even work in. He's a quasar man -- he studies very distant, very luminous galaxies, first discovered in the 1950s and '60s. Much as Darwin's theory of evolution unifies life on Earth, Rector studies and proposes models that might explain all the different types of quasars and how they are related.

Which brings me to my biggest disappointment writing this column about Travis Rector: It's over. And there's so much more to say.

Come back next week for Part II: How to explain the universe to your 4-year-old.

 

 


Kathleen McCoy is an electronic media specialist at UAA, where she highlights campus life through social and online media.

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