An image from the Dark Energy Camera (DECam) shows a striking celestial sight: the Southern Pinwheel Galaxy, a gorgeous face-on galaxy that is one of the closest and brightest barred spiral galaxies in the sky. Also known as Messier 83, the galaxy is bright enough that it can even be seen with binoculars, but this image from a 4-meter Víctor M. Blanco Telescope shows the kind of stunning detail that can be picked out using a powerful instrument.
“This image shows Messier 83’s well-defined spiral arms, filled with pink clouds of hydrogen gas where new stars are forming,” explains NOIRLab from the National Science Foundation, which released the image. “Interspersed amongst these pink regions are bright blue clusters of hot, young stars whose ultraviolet radiation has blown away the surrounding gas. At the galaxy’s core, a yellow central bulge is composed of older stars, and a weak bar connects the spiral arms through the center, funneling gas from the outer regions toward the core. DECam’s high sensitivity captures Messier 83’s extended halo, and myriad more distant galaxies in the background.”
The galaxy is around 15 million light-years away, and appears in the constellation of Hydra. It has famously been imaged by the Hubble Space Telescope as well, thanks to its large size and distinctive spiral shape. It is not to be confused with the Pinwheel Galaxy, another spiral galaxy that has a similar name due to its similar shape, but which is located in a different area of the sky — 110 million light-years away in the constellation of Ursa Major.
The Southern Pinwheel is particularly visible even though it is not that large at around 50,000 light-years across. That’s about half the width of the Milky Way. However, the Southern Pinwheel glows brightly because it is a busy place for star formation, with many new stars being born and glowing brightly in the pink streaks seen in the image.
As well as new stars being born, this is also a region where old stars are dying, and the galaxy has been host to six supernova explosions seen in the last century. There is also evidence of hundreds of thousands of supernova remnantse, which are the ghostly structures left behind by previous supernova explosions. Astronomers study these bubble-shaped structures to learn more about the stars that once lived there before they came to the end of their lives and exploded, throwing out material into the space surrounding them.
