Blue Ribbon Panel Endorses Giant Telescopes as a High Priority
The National Academy of Sciences has released the report of the 2010 Astronomy and Astrophysics Survey Committee. This report lays out their recommendations for scientific priorities in the coming decade. “New Worlds, New Horizons in Astronomy and Astrophysics,” states that among the top scientific priorities are studies of planets around nearby stars and exploration of the epoch of first light in the Universe. These two scientific frontiers are critical parts of the Giant Magellan Telescope (GMT) science case and are areas where we believe the telescope and its instruments will have a major impact. The report strongly endorses the scientific need for extremely large telescopes and, in particular, highlights their potential synergy with the Atacama Large Millimeter Array (ALMA), Large Synoptic Survey Telescope (LSST), and other major facilities under development in the southern hemisphere. GMTO Board Chair Wendy Freedman said, “This is a pivotal step toward the successful completion of this challenging and exciting project. The enormous collective scientific and technical talent in the GMT consortium will allow us to push back the frontiers of astronomy and enable future discoveries. I am delighted at this historic milestone.”
Chicago Adds Strength to GMT Partnership
GMTO Corporation welcomes the University of Chicago as its newest founding member. The University of Chicago brings a legacy of expertise and accomplishment that will complement the other GMTO partners. The University hopes to ensure its long-term future in optical astronomy by participating in this international partnership that will construct the 25-meter Giant Magellan Telescope.
Antonin Bouchez Joins GMT as AO Scientist
Antonin Bouchez has joined the Giant Magellan Telescope (GMT) staff as Adaptive Optics Scientist. He will be responsible for the development of the adaptive optics system for the GMT, collaborating with an international team of experts. Antonin received his Ph.D. in planetary science from Caltech, and later held a post-doctoral position at the W.M. Keck Observatory. Most recently, he was the project manager for the PALM-3000 AO system for the Palomar Hale 5 meter telescope.
Adaptive Optics with the GMT
Under ideal circumstances, the resolving power of an optical system is determined by the number of light waves entering the aperture—the more wavelengths across the aperture of a telescope, the greater the resolving power. Formally, the resolution of a telescope is defined by the “Rayleigh Criterion” and is equal to 1.22λ/D—where λ is the wavelength of observation and D is the diameter of the telescope. For the human eye this “diffraction-limit” is about 1/2 a minute of arc, or 1/120th of a degree. In practice our vision is limited to a resolution ~2–3 times worse than the diffraction-limit due to imperfections in the eye.
A modest sized telescope, say 1 meter in diameter, has a resolving power of 1/8th of a second of arc in the visible. In practice, however, turbulence in the Earth’s atmosphere blurs the images and telescopes larger than 1 meter in diameter rarely, if ever, achieve diffraction-limited performance. Adaptive optics systems correct this unwanted blurring by rapidly deforming a mirror to cancel the phase, or time-of-arrival delays, induced by the atmosphere, resulting in images with far higher resolution. Using adaptive optics, the 25.4 m diameter GMT will resolve detail 5–10 times finer than that seen with the 2.5 m diameter Hubble Space Telescope!