Feature Story

The Science of Star Spots

November 5, 2014 – by Spenser Hickey ’15

Even though Rachael Roettenbacher graduated from Ohio Wesleyan University in 2008, she still collaborates with OWU physics and astronomy professor Robert Harmon, and she returned to campus recently to pass on wisdom to the next generation of astronomy students.

Roettenbacher currently is pursuing a doctorate in astronomy at the University of Michigan, and her work has been partially funded by NASA’s Harriett G. Jenkins Predoctoral Fellowship. She already has earned a master’s in physics from Lehigh University in Pennsylvania and a master’s in astronomy and astrophysics from the University of Michigan.

“My time at OWU was fundamental to getting me to where I am now,” Roettenbacher said during her October 30 visit. “The opportunities available here, with the research opportunities and the support from the faculty, is just a huge asset to getting me to where I am. I still actively collaborate with Dr. Harmon, who was my science research adviser here.”

While at Ohio Wesleyan, Roettenbacher, a double major in astrophysics and mathematics, was selected as one of three college students nationwide to earn the Society of Physics Students’ “Outstanding Student Award for Undergraduate Research” and to represent the United States at the 2008 International Conference for Physics Students held in Cracow, Poland.

Her presentation to current OWU students was focused on her work conducting direct imaging of star surfaces – while most images of stars have been artistic drawings, newer technology makes her work possible.

“Most telescopes don’t really allow us to see the surface of a star; they allow us to see a pinpoint of light,” Roettenbacher explained. “When we make the effective size of the telescope array, which acts in concert as a single telescope, bigger, we are able to resolve the star and see surface features.”

The features are dark regions on the star’s surface that come from internal magnetic fields; Roettenbacher’s research uses direct imaging to verify the older, indirect imaging techniques.

“It can allow us to really connect the models that we have of the solar magnetic field to other stars,” Roettenbacher said of her work’s importance.

“There’s a bit of a disconnect right now about being able to extend those theories to other stars. Being able to directly image them and really see what’s going on in a direct way is going to allow us to connect other stars to the sun.”

She first began looking into this field while she was an undergraduate at Ohio Wesleyan, thanks to opportunities provided by the physics and astronomy department.

“I was able to start doing research very early on in my career here, and I was able to work with an expert on modeling star surfaces, which is something that I’ve come to really enjoy doing,” she said.

After getting her doctorate, Roettenbacher wants to continue exploring interferometry, the new technique that makes direct imaging possible. She’s not sure what exactly that will involve, but it’s clear she’s shooting for the stars.