Launched in 1990, the NASA/ESA Hubble Space Telescope remains the premier UV and visible light telescope in orbit. With well over 1.6 million observations from 10 different scientific instruments, the ESA Hubble Science Archive is a treasure trove of astronomical data to be exploited.
European Space Agency, Vestergaard comma Marianne, 2017, 'Catching the onset of black hole activity in nearby galaxy Mrk 590', 1.0, European Space Agency, https://doi.org/10.5270/esa-3lhp928