Alive and kicking: A new QPE phase in GSN 069 revealing a quiescent luminosity threshold for QPEs

X-ray quasi-periodic eruptions (QPEs) are intense repeating soft bursts from the nuclei of nearby galaxies. Their physical origin is still largely unconstrained, and several theoretical models have been proposed to date. We present here results a recent XMM-Newton observation GSN 069, galactic nucleus where QPEs were first discovered. After about two years absence, reappeared in we detect consecutive separated by much shorter recurrence time than ever before. Moreover, their intensities peak temperatures remarkably different, novel addition QPE phenomenology. study spectral properties all observations assuming either represent an additional emission component superimposed on that disc, or transient evolution disc itself. In former scenario, consistent with black-body region expands factor 2-3 during individual radius order Sun at peak. alternative non-additive originate area 6-30 times smaller quiescent state emission, smallest regions corresponding hottest most luminous eruptions. The reappearance reveals only below luminosity threshold Eddington ratio 0.4 for one million solar masses black hole. disappearance above likely driven quiescence approaching unity high luminosity, making detection challenging, if not impossible, threshold. briefly discuss some consequences our origin. [abridged]