Free Astronomy Magazine May-June 2024

20 by NOIRLab − Josie Fenske The largest DECam image ever released T his colorful web of wispy gas filaments is the Vela Super- nova Remnant, an expanding nebula of cosmic debris left over from a massive star that exploded about 11,000 years ago. Located around 800 light-years away in the constellation Vela (the Sails), this nebula is one of the nearest super- nova remnants to Earth. Though the unnamed star ended its life thou- sands of years ago, the shockwave its death produced is still propagat- ing into the interstellar medium, carrying glowing tendrils of gas with it. This image is one of the biggest ever made of this object and was taken with the state-of-the- art wide-field Dark Energy Camera (DECam), built by the Department of Energy and mounted on the US National Science Foundation’s Víc- tor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Obser- vatory in Chile, a Program of NSF’s NOIRLab. The striking reds, yellows, and blues in this image were achieved through the use of three DECam filters that each collect a specific color of light. Separate im- ages were taken in each filter and then stacked on top of each other to produce this high-resolution color image that showcases the intricate web-like filaments snaking through- out the expanding cloud of gas. This is also the largest DECam image ever released publicly, containing an as- tounding 1.3 gigapixels. The Vela Supernova Remnant is merely the ghost of a massive star that once was. When the star ex- ploded 11,000 years ago, its outer layers were violently stripped away and flung into the surrounding re- gion, driving the shockwave that is still visible today. As the shockwave expands into the surrounding re- gion, the hot, energized gas flies away from the point of detonation, compressing and interacting with the interstellar medium to produce