A Cosmic ‘Candy Cane’ Was Spotted at the Heart of the Milky Way

At some 13.5 billion years old, the Milky Way has every right to be an old scrooge. But even this codger of a galaxy knows how to get glitzy for the holidays.

With a new image of the Milky Way, published last week, scientists have revealed a “candy cane” at the center of our galaxy. But in place of sugar and peppermint extract, the ingredient list for this cosmic confection contains high-energy particles linked to the formation of stars, according to a statement from the University of California, Los Angeles.

The curved, luminous structure isn’t new to scientists, who first observed the “candy cane” in 1983. But the latest image, which captures the feature in more detail than ever before, still marks a milestone. Thanks to observations made with NASA’s Goddard-IRAM Superconducting 2-Millimeter Observer (GISMO) and a separate radio telescope located in Pico Veleta, Spain, astronomers were able to image the central sector of our galaxy in wavelengths of light spanning infrared, radio and microwave.

While these wavelengths fall outside the range naturally visible to humans, they’re thought to hold crucial information about star formation, explains Johannes Staguhn, an astronomer at Johns Hopkins University, in a statement. Homing in on stellar birth could help resolve some long-standing mysteries about our universe’s earliest days, says Staguhn, who published a recent research paper on the observation.

Of particular interest to scientists is the heart of the Milky Way, home to an especially dense set of clouds made up of dust and gas—the starting stuff of stars, which form when pockets within these clouds collapse in on themselves and ignite in nuclear fusion.

In the new image, areas depicted in blue are pockets of star formation in its infancy, emitting in infrared; yellow splotches, including the candy cane’s curved “handle,” denote spots that have been churning out stars for some time. When the charged, fast-moving molecules that swirl within and around these stellar nurseries interact with magnetic fields, they begin to emit radio waves. Features like the candy cane’s straight, 190-light-year-long “spine,” seem to be entirely comprised of a stream of these energetic particles.

Researchers are still searching for the source of the charged molecules that make up this part of the cane. One current theory involves the Sickle—another high-energy galactic feature shown in the new image that astronomers have previously linked with star formation—overlapping with the candy cane’s spine, astronomer Richard Arendt, who also published a recent paper on the observations, says in a statement from NASA. But plenty of mysteries remain at the center of our galaxy, where molecules and cosmic objects of various sizes are frequently colliding.

“We're very intrigued by the beauty of this image,” Staguhn says in the Johns Hopkins statement. “It’s exotic. When you look at it, you feel like you’re looking at some really special forces of nature in the universe.”

Katherine J. Wu | | READ MORE

Katherine J. Wu is a Boston-based science journalist and Story Collider senior producer whose work has appeared in National Geographic, Undark magazine, Popular Science and more. She holds a Ph.D. in Microbiology and Immunobiology from Harvard University, and was Smithsonian magazine's 2018 AAAS Mass Media Fellow.