Two groups of galaxies have been found that are just like ours
An international team of astronomers, led by Dr Aaron Robotham of the International Centre for Radio Astronomy Research (ICRAR), and the University of St Andrews in Scotland, searched for groups of galaxies similar to ours in the Galaxy and Mass Assembly survey (GAMA).
Simulations of how galaxies form have so far not shown many examples similar to the Milky Way and its surrounds, suggesting they would be a rare occurrence. How rare had not been established until now though, with the discovery of two exact matches amongst the hundreds of thousands of galaxies surveyed. About 3% of galaxies similar to the Milky Way have companion galaxies like the Large and Small Magellanic Clouds; there are 14 galaxy systems similar to ours but only two of those are an exact match.
The researchers found that many galaxies have smaller galaxies orbiting around them, but very few have two as large as the Magellanic Clouds. Companions like the Magellanic Clouds are rare, but they are usually found near a galaxy very like the Milky Way.
The image shows one of the two ‘exact matches’ to the Milky Way system found by the research team. The larger galaxy, known as GAMA202627, is similar to the Milky Way. The other galaxies circled are its two large companions. Bluer colors indicate hotter, younger, stars like many of those that are found in our galaxy.
Photo: Aaron Robotham/ICRAR/St Andrews/GAMA