Astronomers in California have taken a telescope built before most of them were born and converted it into a new instrument dedicated to one of the newest and fastest-moving branches of astronomy: spotting objects in the sky that change from one day to the next.
The new Zwicky Transient Facility (ZTF), which today opened its eye to the sky, was created by retooling the 1.2-meter Samuel Oschin Telescope at the Palomar Observatory near San Diego, California, which, starting in 1948, took pictures of the night sky onto specially curved glass photographic plates. The ZTF, named in honor of Fritz Zwicky, the Bulgaria-born astronomer who worked for most of his career at the California Institute of Technology (Caltech) in Pasadena, has been fitted with a new camera made up of 16 charge-coupled device (CCD) detectors. That will enable it to snap single images covering an area more than 200 times the size of the full moon.
With such a wide field of view—the biggest of any telescope more than 0.5 meters wide—the ZTF can survey the whole northern sky visible from Palomar every night. By doing so, astronomers can spot anything that changes from the previous night’s images, enabling them to identify quickly changing celestial phenomena, including supernovae, variable and binary stars, the active cores of distant galaxies, potentially Earth-threatening asteroids, and the flash of merging neutron stars that could also emit gravitational waves.