New Delhi: How does a star take its shape in the universe? It’s a question scientists have answered long back, but star formation remains a poorly understood process.
The formation of a star is an extremely important phenomenon in the universe as it is the principal factor responsible for driving galaxy evolution.
In order to visualise star formation processes within molecular clouds, astronomers from the University of California, Santa Cruz, have developed the first three-dimensionally printed models of stellar nurseries.
Molecular clouds or stellar nurseries are vast areas or clouds of dust and gas in space where stars are formed.
The study was recently published in the Astrophysical Journal Letters. Nia Imara, assistant professor of astronomy and astrophysics at UC Santa Cruz and the first author of the study, created these 3-D models that fit in the palm of her hand to understand the structural complexities of stellar nurseries, UC Santa Cruz explained in a statement.
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What Are 3-D Printed Stellar Nurseries?
This is the first time such structures have been created. They are of the size of a baseball, with a diameter of 8 centimetres, and are highly polished spheres
Star-forming clouds of gas and dust are represented by the swirling clumps and filaments in the 3-D structures. The spheres represented nine different simulations of star-forming clouds.
The researchers also printed half-spheres that show how the middle region of a stellar nursery appears. The low-density regions and voids in stellar nurseries are represented by the darker portions in the models, while the higher density regions of the nurseries are represented by the lighter material.
The fundamental physical processes governing the evolution of molecular clouds in interstellar medium that the nine simulations investigate are: turbulence, gravity and magnetic fields. The scientists note that by changing different variables such as the magnetic field strength, or the speed of gas, the simulations can show how star formation is affected.
James C. Weaver, co-author of the study, said that the models made it easier to spot subtle differences in star formation processes. He explained that they defined the cloud's form with a lot of details by using an inkjet-like 3D printing process, which deposits small droplets of opaque resin at specific places in a surrounding volume of transparent resin.
How Did The Researchers Create 3-D Models?
The researchers used data from simulations of star-forming clouds and a sophisticated 3-D printing process to create the models. The printing process helped them embed the fine-scale densities and gradients of the turbulent clouds in a transparent resin or matrix.
In the UC Santa Cruz press release, Imara said their aim was to create an interactive object that will help them visualise star forming structures in order to better understand the physical processes.
"Years ago, I sketched a portrait of myself touching a star. Later, the idea just clicked. Star formation within molecular clouds is my area of expertise, so why not try to build one?" Imara said.
With the help of high-resolution and photo-realistic 3D printing, the researchers turned the data from the nine astronomical simulations, which represented various physical conditions within molecular clouds, into these spheres.
How Are These Models Useful?
The distribution of density gradients in stellar nurseries is reproduced through these models in a visually stunning manner, the study states.
Co-author John Forbes said not only were the models aesthetically and visually appealing, but also they were an easier way to visualise the complex structures, compared to the usual techniques of visualising the astronomical simulations. He added that one can observe a dimensional sheet having little filaments inside it, within the 3D printed spheres.
Imara said the structures revealed by the models are more continuous compared to 2-D projections. She explained that the models serve as an interactive object which allow an easier detection of the continuities.
The study explains that these models can serve as the basis for analysis of other structurally complex astronomical information like that of nearby molecular clouds of the constellation Orion. Also, the models can be incorporated with different colours to increase their scientific significance. The study also states that these models can be used for education and public outreach endeavours.