A new initiative has been launched by the Space Telescope Science Institute (STScl) in Baltimore, Maryland, using the Hubble Space Telescope called ULLYSES, which stands for UV Legacy Library of Young Stars as Essential Standards. ULLYSES is the largest observation program ever to use the Hubble telescope in terms of the amount of time dedicated to it. Over 300 stars will be included in the observing program.
UV light from the stars is being used to produce a library of the spectral “templates” of young, low-mass stars located in eight star-forming regions scattered across the Milky Way. The survey will also include several mature high-mass stars is in nearby dwarf galaxies, including the Magellanic Clouds. The image above shows archival stars in the Large Magellanic Cloud circled in yellow and observed stars circled in blue.
One primary goal of the ULLYSES observation program is to form a complete reference sample used to create spectral libraries capturing the diversity of stars. Researchers want to create a legacy data set for a wide range of astrophysical topics. The team behind ULLYSES believes the project will have a lasting impact on future research by astronomers globally. STScl has released the first set of ULLYSES observations with early targets including hot, massive, blue stars located in several nearby dwarf galaxies.
One major goal of the program is to better understand how stars are born and how it relates to planet formation and galactic evolution. Astronomers aim to determine how young low-mass stars impact the evolution and compositions of planets forming around them. Researchers say that the intense ultraviolet radiation rips molecules apart and can penetrate circumstellar discs where planet formation occurs.
That UV radiation can influence the chemistry of forming planets and directly impacts how long circumstellar discs survive. There is also a direct impact on planet habitability, atmospheric escape, and chemistry. The program targets massive stars in nearby galaxies where the galaxies have little abundance of heavy elements similar to the primitive composition of early galaxies. The design and target of observations were selected with help from the astronomical community.