Globular Star Cluster Sheds Light on the 'Lithium Problem' in Our Universe

A certain star cluster is not all that it seems, and may shed some light on the chemicals found in our universe. Scientists have taken a closer look at a globular star cluster named Messier 54, one of about 150 that orbit the Milky Way galaxy, and have made some startling new findings when it comes to what is known as the "lithium problem."

For more than 200 years after Messier 54 was first discovered, researchers believed that it was similar to other Milky Way globular star clusters. In 1994, though, scientists found that it was actually associated with a separate galaxy, called the Sagittarius Dwarf Galaxy. In fact, it's located at a distance of about 90,000 light-years, which is more than three times as far from Earth as the galactic center.

Most of the light chemical element lithium was produced during the Big Bang along with hydrogen and helium. In fact, astronomers can calculate how much lithium they expect to find in the early universe, and from this can work out how much they should see in old stars. Yet for some reason, the numbers don't add up.

That's why scientists took a closer look at the stars in Messier 54. Using the Very Large Telescope, the scientists discovered that the levels are close to those in the Milky Way. This means that whatever it is that got rid of the lithium seems to not be specific to the Milky Way.

The findings reveal a bit more about this particular lithium conundrum. That said, more research will have to be conducted before any conclusions are drawn. For now, though, Messier 54 is shedding more light on our early universe.

The findings are published in the journal Monthly Notices of the Royal Astronomical Society.