Hubble reveals the local universe in glorious ultraviolet detail
An international team of astronomers has completed the most comprehensive ultraviolet survey of the local universe to date, with the help of the venerated Hubble Space Telescope. The newly-released survey data will help scientists to better understand how stars come to form, and the processes by which galaxies like our own Milky Way evolve over time.
A grand total of 50 galaxies were observed by Hubble as part of the Legacy ExtraGalactic UV Survey (LEGUS). The specimens selected for the campaign included majestic spiral galaxies similar to our own, and smaller less structurally defined dwarf galaxies located within 60 million light-years of Earth. Each of the galaxies met a selection criteria based on mass, star formation rates, and the abundance of elements heavier than hydrogen and helium.
New visible and ultraviolet light observations of these vast cosmic structures taken with Hubble's Wide Field Camera 3, and Advanced Camera for Surveys, were supplemented with archived images that had been captured by the telescope at an earlier date.
From this wealth of Hubble data, astronomers compiled two massive cosmic catalogues – one containing data on roughly 8,000 star clusters, and a second characterizing some 39 million stars with a mass over five times that of our Sun.
The stars detailed in the new catalogues are super hot, bright, young stellar bodies, which blast out massive amounts of ultraviolet radiation. By observing these stars, and large clusters of them, astronomers hope to lean how they interact with their environment, the processes that govern their dispositions, and to better understand the relationship between star creation and huge galactic elements such as sweeping spiral arms.
Of course, the discoveries and insights that stem from the new data release will not be limited to our own "little" pocket of the universe. In much the same way that astronomers can apply lessons learned from studying the planets of our solar system to distant exoplanets, scientists will be able to use insights gleaned from galaxies in our local universe, to interpret signals from incredibly distant galaxies.
Galaxies detailed in the new catalogues will provide tantalizing targets for future space telescopes, such as the James Webb Space Telescope, which having suffered yet another delay is expected to launch no earlier than May 2020. The power and sophistication of these next-generation telescopes will allow scientists to build on the LEGUS observations, and in so doing heighten humanity's understanding of the vast menagerie of galaxies that populate our universe.
Head to the gallery to see some stunning Hubble imagery of the survey galaxies.
Source: Hubble Space Telescope