Astronomers may now have stellar nurseries in their hands

Researchers can now have stellar nurseries in their schools thanks to 3D printing, revealing features often hidden in traditional representations and animations.

Astronomers cannot touch the stars they study, but astrophysicist Nia Imara uses three-dimensional models that fit in the palm of her hand to unravel the structural complexities of stellar nurseries, the vast clouds of gas and dust where the star occurs. star formation.

Imara and his collaborators created the models using simulation data from star-forming clouds and a sophisticated 3D printing process in which fine-scale densities and gradients of turbulent clouds are embedded in a transparent resin. The resulting models, the first 3D-printed stellar nurseries, are highly polished spheres the size of a baseball (8 inches in diameter), in which the star-forming material appears as rotating filaments and agglomerations.

“We wanted an interactive object that would help us visualize those structures where stars form so we can better understand physical processes,” said Imara, assistant professor of astronomy and astrophysics at UC Santa Cruz and first author of an article that describes this new approach published on August 25, 2021, a Letters from astrophysical journals.

Imara, an artist and astrophysicist, said the idea is an example of science that mimics art. “Years ago I drew a portrait of myself touching a star. Later, the idea clicked. Star formation within molecular clouds is my area of ​​expertise, so why not try to build one? She said.

He worked with co-author John Forbes at the Center for Computational Astrophysics at the Flatiron Institute to develop a set of nine simulations that represented different physical conditions within molecular clouds. The collaboration also included co-author James Weaver of Harvard University’s School of Engineering and Applied Sciences, who helped turn astronomical simulation data into physical objects using high-resolution multimaterial 3D printing. photo-realistic.

The results are visually stunning and scientifically enlightening. “Simply aesthetically they’re really amazing to look at, and then you start noticing the complex structures that are incredibly hard to see with the usual techniques for visualizing these simulations,” Forbes said.

For example, leaf-shaped or panel-shaped structures are difficult to distinguish in slices or two-dimensional projections, because a section through a sheet looks like a filament.

“Inside the spheres, you can clearly see a two-dimensional sheet, and inside there are small filaments, and that’s mind-boggling from the perspective of someone trying to understand what’s going on in these simulations,” Forbes said. .

The models also reveal more continuous structures than would appear in 2D projections, Imara said. “If you have something circulating in space, you may not realize that two regions are connected by the same structure, so having an interactive object that you can rotate in your hand allows us to detect these continuities more easily,” he said. .

The nine simulations on which the models are based were designed to investigate the effects of three fundamental physical processes that govern the evolution of molecular clouds: turbulence, gravity, and magnetic fields. By changing different variables, such as the strength of magnetic fields or the speed with which the gas moves, the simulations show how different physical environments affect the morphology of substructures related to star formation.

Stars tend to form in groups and nuclei located at the intersection of filaments, where the density of gas and dust becomes high enough for gravity to take over. “We believe that the turns of these newborn stars will depend on the structures in which they form; stars in the same filament will” know “about the turns of others,” Imara said.

With physical models, an astrophysicist skilled in these processes does not need to see the differences between the simulations. “When I looked at 2D projections of the simulation data, it was often difficult to see their subtle differences, while with 3D printed models it was obvious,” said Weaver, who has experience in biology and materials science and uses usually 3D printing to investigate the structural details of a wide range of biological and synthetic materials.

“I am very interested in exploring the interface between science, art and education and I am passionate about using 3D printing as a tool for presenting complex structures and processes in an easily understandable way,” Weaver said. “3D printing based on traditional extrusion can only produce solid objects with a continuous outer surface, and this is problematic when trying to represent gases, clouds or other diffuse shapes. Our approach uses an inkjet-like 3D printing process to deposit small individual drops of opaque resin in precise locations within a surrounding volume of clear resin to define the shape of the cloud in exquisite detail. ”

He noted that in the future the models could also incorporate additional information by using different colors to increase their scientific value. Researchers are also interested in exploring the use of 3D printing to represent observation data from nearby molecular clouds, such as those in the constellation Orion.

The models can also serve as valuable tools for education and public outreach, said Imara, who plans to use them in an astrophysics course he will teach this fall.

Reference: “Touching the Stars: Using High-Resolution 3D Printing to Visualize Star Nurseries” by Nia Imara, John C. Forbes, and James C. Weaver, August 25, 2021, Letters from astrophysical journals.
DOI: 10.3847 / 2041-8213 / ac194e