Researchers identified nine new satellites orbiting our galaxy, which is the largest number that has ever been discovered at once.
The findings come from a stunning new photo from the Dark Energy Survey, and could help provide insight into mysterious dark matter, the University of Cambridge reported. The satellites, which are the first to be discovered since 2006, are located in the southern hemisphere near the Large and Small Magellanic Cloud. Cosmological models of the universe predict that there are hundreds of dwarf galaxies orbiting the Milky Way, and these small galaxies are composed of about 99 percent dark matter, making them ideal for dark matter study.
"Dwarf satellites are the final frontier for testing our theories of dark matter," said Vasily Belokurov of the Institute of Astronomy, one of the study's co-authors. "We need to find them to determine whether our cosmological picture makes sense. Finding such a large group of satellites near the Magellanic Clouds was surprising, though, as earlier surveys of the southern sky found very little, so we were not expecting to stumble on such treasure."
The closest of the newly-discovered satellites is located 97,000 light years away in the constellation Reticulum, the farthest is 1.2 million light years away in the constellation of Eridanus; it is right on the fringe of the Milky Way and is about to be pulled in. The distant galaxy appears to contain a globular cluster of stars, which would make it the faintest galaxy to possess one.
"These results are very puzzling," said co-author Wyn Evans, also of the Institute of Astronomy. "Perhaps they were once satellites that orbited the Magellanic Clouds and have been thrown out by the interaction of the Small and Large Magellanic Cloud. Perhaps they were once part of a gigantic group of galaxies that - along with the Magellanic Clouds - are falling into our Milky Way galaxy."
The findings will be published in The Astrophysical Journal.
