News

“Finding Planets Using Pulsating Stars” Will Be Topic For Free Lecture at GTCC

(Released 3/24/2011)

JAMESTOWN - Brad Newton Barlow of UNC-Chapel Hill will give a free public lecture at 7 p.m. Friday, April 8, at Guilford Technical Community College. His topic will be "Finding Planets Using Pulsating Stars."

The lecture will be in the auditorium of the Sears Applied Technologies Building.

"From my perspective, this talk will be interesting because it will tell us about a new method for detecting planets," said Tom English, astronomy professor for physical sciences and director of Cline Observatory.

"Most of the planets astronomers have found outside our solar system have been detected through two specific methods. The method Mr. Barlow will describe adds another tool for us to use to find other worlds," English said

The event is made possible by the GTCC Foundation, Friends of Cline Observatory and GTCC's student astronomy club, the Steller Society.

The Cline Observatory also will be open for viewing after the lecture, weather permitting.

Barlow is a fifth-year Ph.D. candidate in the Department of Physics and Astronomy at UNC-Chapel Hill. His research primarily focuses on the hot subdwarf stars, a class of objects representing one of the least-understood stages of stellar evolution.

He has also collaborated on research projects investigating X-ray binaries, white dwarfs and exoplanets. In addition to research, Barlow is an instrumentation specialist for the Goodman spectrograph on the 4.1-m SOAR telescope on Cerro Pachon in Chile.

Barlow is originally from Biloxi, MS, and did his undergraduate studies at Mississippi State University. He will complete his dissertation this year, after which he plans to working as a postdoctoral student on hot subdwarf asteroseismology.

"Stellar pulsations are important for measuring the internal structure of stars but may also be used to detect the presence of extrasolar planets and other binary companions. Since companions will cause the pulsator to wobble around the system's barycenter, the arrival times of the pulses can be used to detect unseen companions as small as planets like Earth, and characterize the nature of their orbits," according to Barlow.

"As of February of this year, over 500 planets have been confirmed outside of our solar system, and more than 1200 that were recently detected with NASA's Kepler telescope await confirmation," he said.

Most of these systems were discovered either spectroscopically from radial velocity variations in the host star or photometrically from transit observations. These methods are biased in favor of objects with large radii and masses, and, consequently, most exoplanets found to date are gas giants more massive than Jupiter, Barlow said.

Barlow's lecture will present an overview of the light-travel time technique, a method that uses the pulse timings of variable stars to detect stellar and substellar companions down to Earth-size, and also will present intriguing results from specific stars.

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