Free Astronomy Magazine January-February 2022

19 JANUARY-FEBRUARY 2022 ASTRO PUBLISHING NGC 1427A. This ragged patch of light is a small, irregular collection of stars similar to the Large Magellanic Cloud. Similarly to NGC 1404, NGC 1427A is plunging toward the heart of the cluster at roughly 2.2 million kilometers (or 1.3 million miles) per hour. This headlong rush to destruc- tion will eventually result in the galaxy being disrupted — pulled apart by gravitational interactions with other galaxies. As with most astronomical obser- vations, this image shows not only the intended target but also a menagerie of objects both close to home and at tremendous distances. The image is dotted with interloping objects from within our own Milky Way — bright stars with diffraction spikes. At the other extreme, distant galaxies provide a colorful backdrop to this image: some are recognizable as spiral galaxies, while others are mere smudges. Despite appearing tiny in this image, each of the distant galaxies contains billions of stars. This image was captured by the 570- megapixel Dark Energy Camera (DECam), one of the highest-perfor- mance, wide-field imagers in the world, as part of the Dark Energy Survey. Funded by the US Depart- ment of Energy (DOE) and built and tested at DOE’s Fermilab, DECam was operated by DOE and the Na- tional Science Foundation (NSF) be- tween 2013 and 2019. Among its many accomplishments, DECam ob- A doomed galaxy falling into the core of the Fornax Cluster was captured by the Dark Energy Cam- era on the Víctor M. Blanco Tele- scope in Chile. The irregular galaxy NGC 1427A is plunging into the heart of the cluster at 2.2 million kilometers (or 1.3 million miles) per hour. Over millions of years, the galaxy will be ripped apart by gravi- tational interactions from the two largest galaxies in the image. Many colorful galaxies of various sizes and shapes paint the background of this image, appearing alongside nearby stars inside our own Milky Way. [CTIO/NOIRLab/NSF/AURA] servations have helped astronomers discover nearly 300 previously un- known dwarf galaxies in the Fornax Cluster. At present DECam is used for pro- grams covering a huge range of sci- ence. Like other survey instruments, DECam captures images of large swaths of the night sky, allowing as- tronomers to understand structures in the Universe at large scales. Telescope surveys also help identify intriguing astronomical objects wor- thy of follow-up observation; the most powerful telescopes can only study a minute portion of the night sky at any given time, so as- tronomers often use surveys to find objects that are interesting enough to observe in detail. !