Many galaxies in this cluster are already known, but Jean-Charles and his colleagues are interested in the tiny galaxies that were not visible in images from other telescopes.

“We want to see the extremely faint and small galaxies, called dwarf galaxies. They are dominated by older stars that shine in infrared light. According to cosmological simulations, the Universe should contain many more dwarf galaxies than we have found so far. With Euclid, we will be able to see them, if they indeed exist in such a large number as predicted.”