ORONO – While telescopes provide new images of faraway galaxies, scientists are learning what those galaxies have to tell us about how the universe evolved. On April 28, the public will get a chance to hear from an astronomer who studies galaxies that sometimes bear little resemblance to spiral-shaped patterns like the Milky Way.

Debra Elmegreen, Maria Mitchell Professor of Astronomy and chairwoman of the Physics and Astronomy Department at Vassar College in Poughkeepsie, N.Y., will give a free public lecture at 7 p.m. in 101 Neville Hall at the University of Maine.

Her talk, “A Glimpse of Galaxies at the Dawn of the Universe,” is sponsored by the University of Maine Department of Physics and Astronomy and the UMaine Distinguished Lecture Series for the World Year of Physics, 2005.

Elmegreen will describe galaxies observed from a time when the universe was less than one-third its present age. Such galaxies can have a variety of shapes, such as linear chains and tadpoles.

“Spiral galaxies like our Milky Way have a two-dimensional pinwheel shape. In contrast, elliptical galaxies have three-dimensional shapes, and irregular galaxies are less structured. When we view galaxies at high redshifts (farther back in time), we see them as they were when the universe was less than one-third its present age,” Elmegreen said. “Such young galaxies often have very different appearances and properties than present-day galaxies.”

Images from the Hubble and Spitzer space telescopes will be shown to illustrate how galaxies form and evolve, and how their buildup fits into the overall structure and development of the universe.

Elmegreen’s research interests include star formation and the structure of spiral and interacting galaxies. She observes in optical, near-infrared and radio wavelengths. She also is the director of the New York Science Talent Search, a statewide spinoff of the national Intel (formerly Westinghouse) competition for high school seniors.