Exotic 'Proca star' shapes are unstable, collapse or simplify

By solving the Einstein–Proca equations, the authors construct an extended zoo of self-gravitating solitons built from vector (Proca) fields arranged in electric-type, magnetic-type, and hybrid multipolar configurations. Magnetic solutions have no spherical counterpart and carry local angular momentum that cancels globally; some lack north-south symmetry. Numerical evolutions reveal that all new magnetic and hybrid solutions are unstable: they either decay into previously known stable Proca stars (prolate or spinning) or collapse to black holes. The result sharpens understanding of which exotic compact objects can survive as long-lived astrophysical candidates.