BlackGEM: the wide-field multi-band optical telescope array - Groot, Paul J.; Bloemen, Steven; Vreeswijk, Paul M.; Jonker, Peter G.; Pieterse, Danielle; Engels, Arno; Michiels, Jeroen; Bakker, Roy; Hahn, Floris; Raskin, Gert; Morren, Johan; Navarro, Ramon; et al. (SPIE, 2022)