Astronomers cannot touch the stars they study, but an astrophysicist is unraveling the structural complexities of stellar nurseries, the vast clouds of gas and dust where star formation occurs, using 3-dimensional models that fit in the palm of her hand.
The models were created by astronomers using data from star-forming cloud simulations and a sophisticated 3D printing process in which the fine-scale densities and gradients of turbulent clouds are embedded in a transparent resin.
Imara and her colleagues created the models using data from star-forming cloud simulations and a sophisticated 3D printing process in which the fine-scale densities and gradients of turbulent clouds are embedded in a transparent resin. The resulting models of the first 3D-printed stellar nurseries are highly polished spheres about the size of a baseball (8 centimeters in diameter), with swirling clumps and filaments of star-forming material.
“We wanted an interactive object to help us visualize those structures where stars form so we could better understand the physical processes,” said Imara, an assistant professor of astronomy and astrophysics at UC Santa Cruz and the first author of a paper describing this novel approach that was published in Astrophysical Journal Letters.
Imara, an artist as well as an astrophysicist, described the concept as an example of science imitating art. “I drew a portrait of myself touching a star years ago. Later, the thought just came to me. Why not try to build a star within a molecular cloud, which is my area of expertise? “She stated.
We created the models using data from star-forming cloud simulations and a sophisticated 3D printing process in which the fine-scale densities and gradients of turbulent clouds are embedded in a transparent resin.
Imara – assistant professor of astronomy and astrophysics
She collaborated with coauthor John Forbes at the Flatiron Institute’s Center for Computational Astrophysics to create a set of nine simulations that represent various physical conditions within molecular clouds. Coauthor James Weaver of Harvard University’s School of Engineering and Applied Sciences was also involved in the collaboration, helping to turn the data from the astronomical simulations into physical objects using high-resolution and photo-realistic multi-material 3D printing.
The end result is visually stunning as well as scientifically illuminating. “Just aesthetically, they’re really amazing to look at,” Forbes said, “and then you start to notice the complex structures that are incredibly difficult to see with the usual techniques for visualizing these simulations.” Sheet-like or pancake-shaped structures, for example, are difficult to distinguish in two-dimensional slices or projections because a section through a sheet appears to be a filament.
“Within the spheres, you can clearly see a two-dimensional sheet, and inside it are little filaments, which is mind-boggling from the perspective of someone trying to understand what’s going on in these simulations,” Forbes explained.
According to Imara, the models also reveal structures that are more continuous than they would appear in 2D projections. “If you have something winding around in space, you might not notice that two regions are connected by the same structure,” she explained. “Having an interactive object you can rotate in your hand allows us to detect these continuities more easily.”
The models’ nine simulations were created to investigate the effects of three fundamental physical processes that govern the evolution of molecular clouds: turbulence, gravity, and magnetic fields. The simulations show how different physical environments affect the morphology of substructures related to star formation by changing variables such as the strength of magnetic fields or the speed of the gas.
Stars form in clumps and cores at the intersections of filaments, where the density of gas and dust is high enough for gravity to take over. “We believe that the spins of these newborn stars will be determined by the structures in which they form,” Imara said. “Stars in the same filament will ‘know’ about each other’s spins.”
It doesn’t take an astrophysicist with expertise in these processes to see the differences between the simulations using the physical models. “When I looked at 2D projections of the simulation data, it was often difficult to see their subtle differences,” said Weaver, who has a background in biology and materials science and routinely uses 3D printing to investigate the structural details of a wide range of biological and synthetic materials.
“I’m very interested in exploring the interface between science, art, and education, and I’m very passionate about using 3D printing as a tool for presenting complex structures and processes in an easily understandable manner,” Weaver said. “Traditional extrusion-based 3D printing can only produce solid objects with a continuous outer surface, which is inconvenient when depicting gases, clouds, or other diffuse forms. To define the cloud’s form in exquisite detail, we use an inkjet-like 3D printing process to deposit tiny individual droplets of opaque resin at precise locations within a surrounding volume of transparent resin.”
He added that in the future, the models could incorporate additional information by using different colors to increase their scientific value. The researchers are also curious about using 3D printing to represent observational data from nearby molecular clouds, such as those in the constellation Orion. The models can also be used for education and public outreach, according to Imara, who plans to use them in an astrophysics course she will teach this fall.
