B Do Objects in Motion Create Gravitational Waves?

[Ibix]

I'm not sure the question has been answered with all the pushback. I thought it took two massive objects moving near each other to produce gravitational waves. Is that correct? If you say it only takes one, can you prove that with observed data?

So far we have three data points, all of which are for two bodies. However - join the two bodies by a string. Then you've got one body that isn't massively different from a system we've spotted emitting gravitational waves.

More seriously, the source term for gravitational waves is a time varying quadrupole moment - so in principle a dumbell or a rod spinning will produce them. In practice, to produce detectable quantities of gravitational waves you're going to need stellar masses, and we don't have any materials strong enough to avoid simply collapsing into a near-sphere under their own weight at that scale. So I think all detectable sources are likely to be two-body sources for some time to come.