Study shows star formation influenced by environmental conditions

[Buster's Uncle]

Study shows star formation influenced by environmental conditions
New stars are formed in molecular clouds where most of the gas is in the form of molecules.
UPI
By Amy Wallace   |   Sept. 15, 2017 at 2:06 PM    



The golden veil of light cloaks a young stellar object known only as IRAS 14568-6304. It is ejecting gas at supersonic speeds and eventually will have cleared a hole in the cloud, allowing it to be easily visible to the outside Universe. IRAS 14568-6304 was discovered with the Infrared Astronomical Satellite, launched in 1983 as a joint project of the US, the UK and the Netherlands to make the first all-sky infrared survey from space. This particular image was taken by the NASA/ESA Hubble Space Telescope and released on May 26, 2016. It is a combination of just two wavelengths: optical light (blue) and infrared (golden orange). The dark swath running across the image is the Circinus molecular cloud, which is so dense that it obscures the stars beyond. NASA/UPI  | License Photo



Sept. 15 (UPI) -- Scientists at Niels Bohr Institute at the University of Copenhagen have determined that new star formation is influenced by local environmental conditions.

According to the classical model, a star is formed when a prestellar core, a roundish accumulation containing 99 percent gas and 1 percent dust, collapses due to overweight, resulting in the formation of a star in the center of the collapse. This is followed by the formation of a disk of gas and dust rotating around said star.

"This is the star's protoplanetary disk, and planets are thought to be formed in such disks -- planet Earth being no exception," Michael Küffmeier, astrophysicist at the institute, said in a press release.

Researchers from the institute carried out computer simulations of the formation of hundreds of stars, to select nine stars representing various regions in space for more detailed modeling.

Their findings suggest idealized models are lacking in describing details in the process of star formation.

"We started by studying the step before the prestellar cores," Küffmeier said. "And when you have a go at that via computer simulations, you will inevitably have to deal with Giant Molecular Clouds -- which are regions in space dense with gas and dust; regions, where star formation takes place."

The team examined the giant molecular cloud by squeezing it figuratively into a cubical model and ended up with a cube measuring 8 million times the distance between the Sun and the Earth on all sides.

The researchers analyzed the nine different stars in this giant molecular cloud "and in each case we gathered new knowledge about the formation of this particular star," Küffmeier said.

"Since we worked in different regions of a giant molecular cloud, the results from the stars examined revealed differences in e.g. disk formation and disk size, which can be attributed to the influence exerted by local environmental conditions. In this sense we have gone beyond the classical understanding of star formation."

Researchers found that the influence of magnetic fields and turbulence play vital roles in the formation of a star.

"We are able to see how important the environment is for the star formation process," Küffmeier said. "We have thus started on the path to make realistic, quantitative models of the formation of stars and planet, and we will continue digging deeper into this. One of the things we would like examine has to do with the fate of dust in protoplanetary disks -- we want to know how dust and gas are separated, allowing in the end planets to form."


https://www.upi.com/Science_News/2017/09/15/Study-shows-star-formation-influenced-by-environmental-conditions/3381505493511/