astronomyphysicsSTEM AMADO, Ariz. and Barnard College, NEW YORK, January 16, 2019 – A new telescope, the first of its kind, will be unveiled Thursday on its journey to helping scientists capture faint traces of some of the most distant and explosive events in the universe. At a ceremony at the Fred Lawrence Whipple Observatory in Amado, Arizona, researchers will present the prototype Schwarzschild-Couder Telescope (pSCT), an advanced instrument for studying supernovas and other astrophysical sources of high-energy gamma rays.
The telescope was designed by a collaboration of U.S. institutions, including Barnard College. The pSCT was made possible by funding through the U.S. National Science Foundation Major Research Instrumentation program and by the contributions of thirty institutions and five critical industrial partners across the United States, Italy, Germany, Japan, and Mexico. If successful, more like it may be built as part of a hemisphere-spanning network of telescopes that will act as one, enabling the next generation of gamma-ray astronomy.
Professor Reshmi MukherjeeThis telescope is the first of its kind, and to have that opportunity come up is really exciting,” said Reshmi Mukherjee, Helen Goodhart Altschul Professor of Physics & Astronomy at Barnard College and the principal investigator at Barnard on the project.
Large optical telescopes use bowl-shaped mirrors to collect visible light rays and focus them for observation. Gamma-ray telescopes measure gamma radiation, which is the shortest-wavelength light there is and the most energetic. Gamma rays (or photons, as light can be considered a wave or a particle) are filtered by the Earth’s atmosphere before they reach ground-based telescopes. However, when a gamma-ray photon strikes a particle in the atmosphere, the collision produces flashes of blue light called Cherenkov radiation. Mirrors on the ground can capture and focus that light on a camera, which records the image at a very rapid rate.
The German physicist Karl Schwarzschild proposed the two-mirror telescope design in 1905, and the French astronomer André Couder modified the design soon after, but for a century an actual telescope of their design was too difficult to build, because of the precision required in the mirrors. Finally, technology has caught up, thanks to critical research at both the Brera Astronomical Observatory and Media Lario Technologies Incorporated in Italy. In the SCT, a mirror facing the sky focuses light on a smaller mirror facing it, which focuses the light on a camera between the two mirrors. This extra step allows for a smaller, more sensitive camera. “There is a lot of need to get these high-resolution, high-energy images, which we just haven’t been able to measure yet,” Mukherjee said.
Three major gamma-ray astronomy facilities are currently in operation, using technology a decade or more old: MAGIC, in the Canary Islands, HESS, in Africa, and VERITAS, at the Whipple Observatory in Arizona. Each combines the signals from two to five telescopes. “These have been very successful, path-finder observatories, but now there’s a huge effort to think of the next step,” said Mukherjee, who is the elected spokesperson of the approximately 100 scientists using VERITAS. That next