Old star clusters could have been the birthplace of supermassive stars

Milky Way
Credit: CC0 Public Domain

A team of international astrophysicists may have found a solution to a problem that has perplexed scientists for more than 50 years: why are the stars in globular clusters made of material different to other stars found in the Milky Way?

In a study published by Monthly Notices of the Royal Astronomical Society, the team led by the University of Surrey, introduce a new actor to the equation that could solve the problem—a supermassive star.

The Milky Way galaxy hosts over 150 old globular clusters, each containing hundreds of thousands of densely packed together and held by gravity—these stars are almost as old as the Universe. Since the 1960s, it has been known that most stars in these clusters contain different chemical elements than all other stars in the Milky Way—these could not have been produced in the stars themselves because the required temperatures are about 10 times higher than the temperatures of the stars themselves.

The Surrey scientists argue that a supermassive star, with a mass that is tens of thousands times the mass of the Sun, formed at the same time as the globular clusters. At that time, globular clusters were filled with dense gas out of which the stars were forming. As the stars collect more and more gas, they get so close to each other that they could physically collide and form a supermassive star in a runaway collision process. The supermassive star was hot enough to produce all the observed elements and "pollute" the other stars in the cluster with the peculiar elements we observe today.

Lead-author Professor Mark Gieles of the University of Surrey said: "What is truly novel in our model is that the formation of the and the globular clusters are intimately linked, and this new mechanism is the first model that can form enough material to pollute the cluster, and with the correct abundances of different elements, which has been a long-standing challenge."

The team proposes various ways to test this new model of globular clusters and supermassive star formation with existing and upcoming telescopes, which can peer deep into the regions where the formed, when the Universe was very young.

Professor Henny Lamers, co-author of the study from the University of Amsterdam, said: "There have been many attempts to solve this problem that has puzzled astronomers for decades and I believe that this is the most promising explanation that has been proposed so far. "I am especially proud that this study is the result of a collaboration between a group of my ex-students and colleagues who are experts in different branches of astronomy."


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More information: Mark Gieles et al, Concurrent formation of supermassive stars and globular clusters: implications for early self-enrichment, Monthly Notices of the Royal Astronomical Society (2018). DOI: 10.1093/mnras/sty1059
Citation: Old star clusters could have been the birthplace of supermassive stars (2018, June 21) retrieved 22 May 2019 from https://phys.org/news/2018-06-star-clusters-birthplace-supermassive-stars.html
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Jun 21, 2018
The complete lack of understanding of processes in the universe, another unimaginative šekulacija is declared "this is the most promising explanation that has been proposed so fa"

"The beginning of the formation of galaxies can be recognized in the planetary and stellar systems. ..
The forces of attraction and the rotation of stars firstly form binary systems. Since rotation and the force of attraction are constant processes, binary systems grow into clusters (there are ~150 of the globular stellar clusters). http://www.svemir...s-formed
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Jun 21, 2018
"What is truly novel in our model is that the formation of the supermassive stars and the globular clusters are intimately linked, and this new mechanism is the first model that can form enough material to pollute the cluster, and with the correct abundances of different elements, which has been a long-standing challenge."


Of coarse, it is the supermassive core star that eventually grows into an intermediate 'grey' hole, ejecting newly formed matter therefrom all the while, polluting the cluster with the peculiar elements. The cluster forms due to the core star's accelerated growth, not by some fanciful merger scenario insisted upon by the merger maniacs.

Don't remain confused by cosmologists. They are lost in their math mania. Their method has them confused.

Jun 21, 2018
Since you guys don't need numeracy, why'd you even bother with reading and writing? Ignorance is your key to heaven. Go for the gusto and gain a principality!

You'll look simply adorable in the robes and flapping wings and shiny halo. Yes you will! As cute as a button, I'm sure.

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