Most of the light chemical element lithium now present in the Universe was produced along with hydrogen and helium during the Big Bang but in much smaller quantities. Astronomers have calculated how much lithium they expect to find in the early Universe and from this work out how much they should see in old stars. But the calculations don’t match the observed values. There is about one-third of lithium in stars that we expect to see in our galaxy, The Milky Way.
This new image from the VLT Survey Telescope at ESO’s Paranal Observatory the globular cluster Messier 54, a star cluster that doesn’t belong to the Milky Way but is part of a small satellite galaxy, the Sagittarius Dwarf Galaxy. A team of astronomers has used the VLT to measure how much lithium there is in a selection of stars in Messier 54. They find that the levels are close to those in the Milky Way. So, whatever it is that got rid of the lithium seems not to be specific to the Milky Way.
Image Credit: ESO