UF astronomy team among first to use massive new telescope

June 18, 2009

GAINESVILLE, Fla. — A team of University of Florida astronomers is among the first in the world to make scientific-quality observations of the heavens using the newly completed Gran Telescopio Canarias, the world’s largest optical telescope.

The team headed by Eric Ford, an assistant professor of astronomy, used the Canary Islands-based GTC to observe a known star and its Jupiter-sized orbiting planet as part of an effort aimed in part at learning how planets contract in size as their stars age. With analysis of the data from the observations now under way, the team also hoped to glean insights about how to tune the GTC’s capabilities to study not only huge, gaseous Jupiter-size planets but also Neptune-sized or “super-Earth”-sized planets that could be closer in composition to Earth.

“The excellent site and large size of the GTC plus the unique filtering capabilities of its detectors will allow astronomers to minimize the effects of Earth’s atmosphere,” Ford said. “By repeatedly measuring the color of exoplanets’ host stars, astronomers can study the atmospheres of exoplanets — and distinguish small planets from other phenomena such as large star spots or binary stars.”

The UF team’s late-May observations were among several announced earlier this week by the Instituto de Astrofisica de Canarias that marked the long-awaited scientific debut of the GTC, first launched in 2000 on the island of La Palma, and only recently completed. UF contributed $5 million to the roughly $180 million telescope and owns a 5 percent share – the only U.S. institution with an ownership stake in the telescope. The Spanish government owns 90 percent, with Mexico owning the remaining 5 percent.

The GTC’s unique 34.1-foot primary mirror, composed of 36 hexagonal segments, gives it unparalleled abilities to see deep into the universe and examine distant objects in great detail. The telescope is equally notable for the ultra-precise computer control of its mirror segments — control that makes possible more finely detailed images than achievable with other telescopes. Its size and controllability makes the GTC powerful enough to detect an ordinary candle from 20,000 miles away — and resolve the width of its flame from six miles away.

UF astronomers say they will use the telescope to learn more about what occurred in the earliest years of the universe, how stars, planets and galaxies come into being, and to discover and learn more about planets outside our solar system.

“We made this investment because we want our excellent faculty and students to have as much opportunity as possible for top-class research,” said Stan Dermott, chairman of the astronomy department. “In astronomy, that requires access to the best facilities.”

Ford, graduate student Knicole Colón, and postdoctoral associates Brian Lee and Suvrath Mahadven, tapped a Spanish-built astronomical instrument, OSIRIS, to gather the data on the extrasolar star, HAT-P-3, and its planet, HAT-P-3b.

However, A UF-designed and built instrument, CanariCam, is anticipated to be the second instrument installed on the GTC. Among other goals, CanariCam will explore origins and early evolution of planetary systems by imaging the protoplanetary disks where planets are born. UF astronomers also made significant contributions to a third instrument expected to be installed on the GTC known as FRIDA.

“The University of Florida is a partner not just in the observing sense,” Dermott said. “We are also a partner in the sense of being the major builder of instruments for the telescope.”

The GTC’s first, ceremonial observations occurred in 2007, before the telescope’s mirror was complete. A formal inauguration is planned for July 24 on the island of La Palma. King Juan Carlos I and Queen Sofia of Spain will preside over the ceremony.