Galactic Ballet captured with a state-of-the-art dark powered camera

These interacting galaxies are located in the direction of the constellation Horologium in the southern celestial hemisphere, about 60 million light-years from Earth. The wide field of view of this observation reveals not only the entangled galaxies, but also their starry surroundings. The frame is full of bright stars in the foreground[{“ attribute=““>Milky Way and is set against a backdrop of even more distant galaxies.

The image was taken with one of the highest-performance wide-field imaging instruments in the world, the Dark Energy Camera (DECam). This instrument is perched atop the Víctor M. Blanco 4-meter Telescope and its vantage point allows it to collect starlight reflected by the telescope’s 4-meter-wide (13-foot-wide) mirror, a massive, aluminum-coated, and precisely shaped piece of glass roughly the weight of a semi truck. After passing through the optical innards of DECam — including a corrective lens nearly a meter (3.3 feet) across — starlight is captured by a grid of 62 charge-coupled devices (CCDs). These CCDs are similar to the sensors found in ordinary digital cameras but are far more sensitive, and allow the instrument to create detailed images of faint astronomical objects such as NGC 1512 and NGC 1510.

An even wider crop of the NGC 1512 image. Credit: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA, Image processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), J. Miller (Gemini Observatory/NSF’s NOIRLab), M. Zamani & D. de Martin (NSF’s NOIRLab)

Large astronomical instruments such as DECam are custom-built masterpieces of optical engineering, requiring enormous effort from astronomers, engineers, and technicians before the first images can be captured. Funded by the US Department of Energy (DOE) with contributions from international partners, DECam was built and tested at DOE’s Fermilab, where scientists and engineers built a “telescope simulator” — a replica of the upper segments of the Víctor M. Blanco 4-meter Telescope — that allowed them to thoroughly test DECam before shipping it to Cerro Tololo in Chile.

DECam was created to conduct the Dark Energy Survey (DES), a six-year (2013-2019) observational campaign involving more than 400 scientists from 25 institutions in seven countries. This international collaboration aims to map hundreds of millions of galaxies, discover thousands of supernovae, and discover subtle patterns of cosmic structure – all to provide much-needed detail about the mysterious dark energy that’s accelerating the expansion of the universe. Today, DECam is still used in programs by scientists around the world and continues its legacy of cutting-edge research.