Not every image produced these days is a simple two-dimensional image. Astronomers using the ‘glue’ visualization software have released a three-dimensional image and interactive figure of the star-forming region in Orion. And in creating their work, they made a discovery about the origin of Barnard’s Loop, an intriguing semicircle first observed back in 1894.

The results of the work were also presented at last week’s AAS meeting, and the study used data from Gaia, of course, to determine the 3D position and velocities of the young stars and clouds in Orion. Lead author Michael Foley explains: Prior to this work, most studies of Orion were confined to two dimensions — up-down and left-right on the sky. By adding in the third dimension — distance — we can begin to map out all sorts of interesting structures, like huge cavities of gas and dust or clusters of stars with very interesting motions. Combining the information from the interstellar gas and stars leads us to believe cavities were produced by a number of supernovae over the last few million years.

One of those newly discovered cavities corresponds with Barnard’s Loop, which is made of hot gas. There is evidence that a certain cluster of stars produced one more supernova and created a bubble that matches that arc of hot gas.

Additionally, much of the new star formation in Orion appears to be happening on the edges of these cavities. So stars go supernova, which pushes out all the gas and dust in a bubble around the star, which then triggers more star formation. Co-author Alyssa Goodman notes: It seems clear that we are going to see a ‘swiss cheese’ picture of the interstellar medium, with stars forming at the edge of the holes, as we map more and more of the galaxy.

The results of this study are consistent with the results of a previous study done by the team on the Per-Tau Supershell Local Bubble around the Sun. The current study is available online as a preprint. We’ll have a link in our show notes.

More Information

CFA press release

“A 3D View of Orion: I. Barnard’s Loop,” Michael Foley et al., 2022 June 16, Authorea (preprint)