Axions belong to most viable dark matter particle candidates currently. Examples are QCD axions and Fuzzy Dark Matter.
I'll show that in such class of models a significant part of dark matter may consist of Bose-stars.
Their condensation, even from virialized state, occurs due to universal gravitational interactions and does not require additional assumptions.
After reaching critical mass an axion Bose-star becomes unstable. Subsequent collapse is peculiar, leading to Bose-nova,
while black hole does not form. I also discuss various astrophysical implications of axion star existence,
in particular possible relation to mysterious Fast Radio Burst phenomena.|