The first galaxies in the Universe probably played a major part in reionization—the event in which primordial gas was turned into a plasma. However, observations of this era are very hard: we’re looking back in time to when the first stars formed, over 95% of the total age of the Universe. As a result, the new discovery of a possible galaxy from 500 million years after the Big Bang is significant…and based on how they found it, its discoverers think it might be just one of many such galaxies.

The astronomers observed 12 galaxy clusters in a small region of the sky. Galaxy clusters are the most massive objects in the Universe bound together by gravity, so they are capable of being powerful gravitational lenses—distorting space in a way that magnifies the light from still more distant objects. The researchers found an object in the region of the galaxy cluster MACS J1149+2223 that appeared to correspond to a magnified galaxy. [Read more….]

The galaxy from the dawn of time