If A Star Is Born borrows a bit from actress Gaga’s real-life early pop career (which Gaga herself has not revealed, though the comparisons are hard to ignore), the character at the center of Vox Lux is pure fiction. However, according to Portman, her role was inspired by gems of truth about this particular kind of celebrity. In, Portman revealed she watched a lot of pop music documentaries to prepare for her role of Celeste.