Westmont Magazine Starry, Starry Night
Michael Sommermann has a job that keeps him up nights. The physics professor not only teaches classes during the day, but he spends moonless evenings operating Westmont’s Keck Telescope. In the past few months, he has confirmed the discovery of a supernova and photographed a comet’s unexpected brightening. It’s been an eventful first year for the powerful new instrument.
“These experiences illustrate the value of astronomical research at Westmont and the potential for future searches and collaborations with other astronomers,” Sommermann says. “It’s important to me as a teacher — and to all our science departments — to involve students in meaningful research. This activity sets our alumni apart when they apply to graduate schools.”
His own field, theoretical nuclear physics, provides limited opportunities for undergraduate work. But astronomy is ideally suited for college students.
“Working with the telescope enables students to apply the principles of physics and Newtonian mechanics,” Sommermann says. “They can do complex measurements of the orbital and rotational motions of asteroids and measure the light curves of pulsating stars and other celestial objects. Operating the instrument also involves mathematics and computer science. In fact, we’ve found that astronomy is a good way to get students from a wide range of majors involved in the sciences.”
While Sommermann and his students can look through the telescope and identify a multitude of stars and galaxies, most of the research requires high-resolution imaging with computer-controlled CCD cameras. But even with these exquisitely sensitive detectors it can take 12 hours or more to produce an astrophotograph like the one illustrating this article (right). Sommermann compiles and combines hundreds of indi-vidual, two-minute exposures each taken with a different color filter. The various colors reveal different types of astronomical information. For instance, reddish globules represent hydrogen-emission nebulae, while bluish areas involve star light scattering off of interstellar dust clouds.
The Keck Telescope is powerful enough to identify supernovae, dying stars that emit a huge burst of light as they collapse. Sommermann was excited to confirm the recent discovery of such a cataclysmic event by astronomical investiga-tors Jack Newton and Tim Puckett. Within 48 hours of receiving a private communica-tion from Tim Puckett, Sommermann spent several early morning hours imaging Supernova 2008an. The phenomenon is clearly visible in one of the spiral arms of UGC 10936, a galaxy about 400 million light years away (see the small photo at right).
“Supernova 2008an appears so bright in the CCD image because it shines with the power of several billion stars,” Sommermann says. “Supernovas are like standard candles that allow us to measure cosmic distances and the Hubble constant and determine the age of the universe.”
Sommermann is fine-tuning the new Keck Telescope and testing the CCD cameras from Apogee Instruments and the Santa Barbara Instruments Group. The telescope, a 24-inch F/8 Cassegrain reflector with Ritchey-Chretien optics, was built by DFM Engineering of Longmont, Colo. “We’re so excited to have this world-class instrument available on campus,” he says.