Found by the Wide Field Camera 3 shortly after its installation during the last Hubble Space Telescope servicing mission in May 2009 and observed at the very edge of Hubble’s supported infrared wavelength band, the object appears as a faint blue dot within the recorded images. Individual stars within the galaxy cannot be resolved by Hubble, but scientists believe the object is a compact galaxy of stars formed from gas trapped in a pocket of dark matter 100 to 200 million years prior to the observation period.
Scientists have previously detected galaxies around 150 to 200 million years younger than this new galaxy at significant numbers but the number of formed galaxies is clearly much lower at this earlier time. This decrease in galaxy formation at around 500 million years after the big bang (or, more accurately, an increase in galaxy formation between 500 million and 650 million years after the big bang) is consistent with the hierarchical theory of galaxy formation in which dark matter plays a large role. This new Hubble data will help further refine theories about early galaxies and how they form.
This new galaxy is right at the very limit of Hubble’s observational range. Scientists hope to use Hubble’s successor, the James Webb Space Telescope, to view galaxies even further away and thus closer to the big bang and at an earlier time in their evolution. In doing so, they hope to develop an even better understanding of the way galaxies are formed and how they change during the early stages of their life cycle.
TFOT has previously reported on other recent Hubble Space Telescope research including images of an asteroid or comet colliding with Jupiter, images of the atmosphere of an exoplanet, and the discovery of the smallest object ever seen with visible light (found by Hubble in the Kuiper Belt).
Read more about the discovery of this new distant galaxy in this NASA press release or in this University of California at Santa Cruz news article. Follow ongoing research and discoveries related to distant galaxies at the First Galaxies website run by UCSC.