Academics and Research / Magazine Feature

DU astronomy department is up to big, big things

Astronomers think big. Really big. Big as in spaces so vast that light itself takes thousands of years to bridge them, and big as in spans of time that are measured in billions of earth years.

When it comes to thinking that big, often exploration isn’t done solely with a powerful telescope, but also with a researcher’s imagination and intellect.

Instead of using an image they can see through a telescope’s eyepiece, researchers often depend on analysis of the raw data that comes in from around the world. By examining the numbers, researchers help observers understand what the images they collect tell us about the origins of stars and solar systems and in interactions going on across galaxies.

“You have to juggle different views in your mind, and it’s not always easy,” says Assistant Professor of astronomyJennifer Hoffman.

“You have to ask yourself, ‘What is my perspective from here, on earth, spinning around? What would this look like if I were able to get off the earth and look back at this from another point?’’

The team

Hoffman has teamed with East Tennessee State University professor Richard “Rico” Ignace on a five-year, $1-million project funded by the National Science Foundation to make measurements of massive stars in polarized light. The light can illuminate the geometrical structures of the stellar “winds” in space.

Stellar winds are outflows of material (mostly hydrogen atoms) from a star’s surface. The sun has such a wind, dubbed the “solar wind,” but it’s gentle. Massive stars have much faster, more turbulent winds, and scientists studying those winds can glean information about the activity below a star’s surface.

The team will involve post-graduate researchers, graduate students and even some undergraduates in creating 3-D computer simulations of the stellar surroundings that can explain polarized-light measurements. It’s expected these simulations will help researchers understand the violent winds of massive stars and how these stars can end up as supernova explosions.

Teaming up with Ignace was a natural, Hoffman says. He specializes in the study of massive stars, and she studies supernova blasts. And with technology, researchers don’t need to be on the same university campus, or even in the same state, to share insights.

“It’s a way of pooling expertise,” Hoffman says.

Stellar cycles

In another DU project aimed at unlocking the secrets of the skies, Assistant Professor Toshiya Ueta deals in spaces and time frames so large, they boggle the mind. Ultimately, his research involves the massive lifecycle of material in space, from how stars are formed to how matter turns into planets and systems, and eventually how they come apart, only to start the cycle over.

In recent projects, Ueta has examined the roles of stellar “dust” — particles emanating from stars — as they come apart in the streams of matter that power through space. In examining such stars as the far-off Mira, Ueta has studied the giant tails of dust-rich material as the stars almost start to look like monstrous comets with stellar wind colliding with the interstellar medium of space.

As he points out, space is not a void, it’s full of material, and with everything in motion, interaction is inevitable.

“Mira is the first case in which astronomers can look into details of this kind of interaction,” Ueta says. “This helps us understand how the universe is filled up [and] with what kind of matter.”

Why study things so far away that they are invisible to all but the most sensitive methods of detection? Why apply theories to data so complex that mysteries take years to unravel?

“It all sort of matters at the level that music matters,” Ignace says. “It’s not food or shelter or clothing, but it matters in that our lives would be poorer without it.”

“It’s our human nature to want to understand our surroundings,” Hoffman adds. “We’re never just going to say, ‘We’re done.’ We can never know ‘enough.’”

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