Regardless of their size, it seems that all galaxies have some strange features in common.
Astronomers have made a breakthrough in finding that all galaxies, regardless of their size, rotate every billion years.
On Earth we measure time based on the rotation of our planet around its axis. A complete rotation is one day and a complete orbit around the Sun is one year.
Our galaxy, called the Milky Way, is between 100.000 and 180.000 light-years in diameter, depending on where it is measured.
Scientists have discovered that at the edge of our galaxy, like any other, the period of rotation lasts a billion years.
"It does not have the accuracy of Swiss watches. "But whether a galaxy is very large or very small, if you could sit on its edge as it spins, it would take about a billion years to complete the entire rotation," said Professor Gerhard Moorer of the International Center for Radio Astronomy Research.
Continuing, the professor explained that all galaxies of the same size have the same average internal density.
"Discovering such a regularity in galaxies helps us better understand the mechanisms that make them move. You will not find a dense galaxy spinning fast and another of the same size but with a lower density spinning more slowly.
Moorer's team also found that large stars in the last years of their "life" are on the edge of galaxies. "Based on existing models, we expected to find a small population of new stars on the edge of the galaxies we studied. "But instead of finding only gases and newly formed stars at the edges, we found a significant number of older stars along with a few new stars and interstellar gas," he added.
He continued: "This is an important conclusion because knowing where the galaxy ends up, astronomers can limit their research and not waste time, effort and energy studying data beyond this point. "So, because of this discovery, we now know that galaxies rotate once every billion years, with an edge full of interstellar gas and old and new stars."
The professor said that this information is vital for the next generation of radio telescopes that will carry huge amounts of data when examining the sky.
For telescopes, such as the SKA under construction, which can detect the edge of a galaxy, this data will be easier to search.
"When SKA is activated in the next decade, we will need as much help as possible to characterize the billions of galaxies that these telescopes will make available to us," Moorer said.
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Source: News247