Astronomers using the Hubble Space Telescope have captured the most comprehensive picture ever assembled of the evolving Universe - and one of the most colorful.
The study is called the Ultraviolet Coverage of the Hubble Ultra Deep Field (UVUDF) project.
Prior to this survey, astronomers were in a curious position. They knew a lot about star formation occurring in nearby galaxies thanks to UV telescope facilities such as NASA's Galex observatory, which operated from 2003 to 2013. And, thanks to Hubble's near-infrared and visible capability, they had also studied star birth in the most distant galaxies.
However, between 5 and 10 billion light-years away from Earth - corresponding to a time period when most of the stars in the universe were born - there was a lack of the data needed to fully understand star formation.
The hottest, most massive and youngest stars, which emit light in the ultraviolet, were often neglected as subjects of direct observation, leaving a significant gap in our knowledge of the cosmic timeline.
With the addition of ultraviolet light, they have combined the full range of colors available to Hubble, stretching all the way from ultraviolet to near- infrared light. The resulting image, made from 841 orbits of telescope viewing time, contains approximately 10,000 galaxies, extending back to within a few hundred million years of the Big Bang.
Since the Earth's atmosphere filters most ultraviolet light, this work can only be accomplished with a space-based telescope like Hubble. Ultraviolet surveys like this are incredibly important in planning for the James Webb Space Telescope (JWST) as Hubble is the only telescope currently able to obtain the ultraviolet data that researchers will need to combine with infrared data from JWST.