HAWAIIAN TELESCOPE TEAM MAKES DEBUT DISCOVERY

NASANews@hq.nasa.gov
Extracted from:- RELEASE: 03-223

Astronomers have observed a young star ringed by a swirling disc that may spin off planets, marking the first published science observation using two linked 10-meter (33-foot) telescopes in Hawaii.

The linked telescopes at the W.M. Keck Observatory on Mauna Kea, known as the Keck Interferometer, comprise the world's largest optical telescope system. The observation was made of DG Tau, a young star that has not yet begun to burn hydrogen in its core. Such stars are called T-Tauri objects. Observations of DG Tau were made on October 23, 2002, and February 13, 2003, and the findings will appear in an upcoming issue of the Astrophysical Journal Letters.

"We're trying to measure the size of the hot material in the dust disc around DG Tau, where planets may form," said Dr. Rachel Akeson, leader of the study team and an astronomer at the Michelson Science Center at the California Institute of Technology in Pasadena. "Studies like this teach us more about how stars form, either alone or in pairs, and how planets eventually form in discs around stars."

The Keck Interferometer observations revealed a gap of 18 million miles between DG Tau and its orbiting dust disc. Akeson notes that of the extra-solar planets - planets orbiting other stars - discovered so far, roughly one in four lies within 10 million miles of the parent star. Since planets are believed to form within a dust disc, either DG Tau's disc has a larger-than-usual gap, or the close-in planets form farther from the star and migrate inward.

Since 1995, astronomers have detected more than 100 extra-solar planets, many considered too large and close to their hot, parent stars to sustain life. By measuring the amount of dust around other stars, where planets may form, the Keck Interferometer will pave the way for NASA's Terrestrial Planet Finder mission. Terrestrial Planet Finder will look for smaller, Earth-like planets that may harbor life. The Keck Interferometer and Terrestrial Planet Finder are part of NASA's Origins Program, which seeks to answer the questions:

Where did we come from?  Are we alone?