This may seem like a silly question. However, what are the conditions for a matter source to produce a non-spherically symmetric gravitational field?
More specifically, can a spherical source produce a non-spherically symmetric field or is this nonsense?
After some reading around. It appears that due to uniqueness theorems or "no hair" theorem for black holes, after sufficiently long times we tend to the conclusion that black holes can only be distinguished by 3 parameters: Mass (energy), charge and angular momentum. So shape of the body (pre-collapse) is essentially irrelevant. Have I understood this correctly?