H I G H L I G H T S
STELLAR DISCOVERIES White dwarfs are the extremely dense end-states of stars like the sun that have collapsed to form an object approximately the size of the Earth. Composed mostly of carbon and oxygen, white dwarfs slowly cool and fade over billions of years. The object in the new study is likely the same age as the Milky Way, approximately 11 billion years old. •••••
Robo-AO Collaboration
An international team is using the world’s first robotic laser
ABOVE : The ultraviolet Robo-AO laser at the California Institute of Technology’s Palomar Observatory.
UNC astronomers Bart Dunlap and Nicholas Law played a
Mary Lide Parker
key role in exciting summer 2014 discoveries involving white dwarf stars and exoplanet systems (planets around other stars). A team of astronomers including Dunlap, a graduate student and research assistant in physics and astronomy, identified possibly the coldest, faintest white dwarf star ever detected. The ancient stellar remnant is so cool that its carbon has crystallized, forming — in effect — an Earth-size diamond in space.
adaptive optics system — Robo-AO — to explore thousands of exoplanet systems at resolutions approaching those of the Hubble Space Telescope. Law is Robo-AO’s project scientist and an assistant professor in UNC’s department of physics and astronomy. Research assistant Carl Ziegler from UNC is also a member of the Robo-AO team. The results shed light on the formation of exotic exoplanet systems and confirm hundreds of exoplanets. Analysis of the first part of the Robo-AO/Kepler survey is already yielding surprising results. “We’re finding that ‘hot Jupiters’ — rare giant exoplanets in tight orbits — are almost three times more likely to be found in wide binary star systems than other exoplanets, shedding light on how these exotic objects formed,” Law said. • Read more about both discoveries at go.unc.edu/Xx75Z and go.unc.edu/Hq25R.
E X A MINING AC TIVE LE ARNING IN L ARGE SCIENCE CL A SSES
In large college science classes, active learning
interventions improve achievement for everyone, but especially black and first-generation students, according to a UNC study. When a traditional lecture course was structured to be more interactive, the achievement gap for first-generation students disappeared, and for black students decreased by half, according to Kelly Hogan, a biologist and director of instructional innovation in the College. She was invited to a September 2014 White House summit on science, technology, engineering and Kelly Hogan mathematics (STEM) education. Hogan’s study, “Getting Under the Hood: How and for Whom Does Increasing Course Structure Work?” appeared Sept. 2 in the journal CBE-Life Sciences Education. Her co-author is Sarah L. Eddy of the University of Washington in Seattle. The two collected data over six semesters at UNC. The study, featured in The New York Times and elsewhere,
compares student achievement in classes with “low course structure” to those with “higher course structure.” Low course structure is “a traditional classroom where students come in, listen to the instructor, leave and don’t do anything until the night before the exam,” Hogan said. Higher course structure adds guided reading questions, preparatory homework and in-class activities that reinforce major concepts, study skills and higher-order thinking skills. As an example of an in-class activity, students answered questions using classroom-response software on their laptops and cellphones. Students are held accountable for the assignments — they are awarded points for being prepared and participating in class. Hogan’s study is one of the few college-level studies to separate student data by racial/ethnic groups and first-generation status to identify which interventions work best for certain groups of students in a large STEM course. The researchers used surveys at the end of the course to learn how the interventions affected student behaviors and attitudes. •
CAROLINA ARTS & SCIENCES • FALL 2014 • COLLEGE.UNC.EDU • 5