How about just doing some more precise measurements first? I'm 99.99% certain that the high density estimate stops existing afterwards
Also, how exactly do you want to get an object without guidance or comms near enough to a main-belt asteroid?
This is all just ridiculous. Some theoretical physicist does some calculation around the Island of Stability, comes up with a high density, and tries to give his paper more relevance by finding an improbably dense astronomical object, and then wildly speculates that the two are related.
What are the chances that some rando asteroid consists of 100% of an element that we
1) don't know if it actually is stable
2) don't actually know the density of, besides a single paper about it
3) don't know any natural, plausible mechanism for synthesis
as opposed to it just being not well studied?
You're right of course about the density being a wild guess, probably not worth pursuing because the odds of finding something interesting are just about 0.
Couldn't this mass be much more accurately estimated by sending a small probe of known mass by the asteroid at a known distance and velocity, and measuring the trajectory perturbation?
I think this could be done with a 5kg radar reflector. No guidance, no comms, no onboard electronics at all. Terrestrial radar measurements of position and velocity are extremely accurate. The launch wouldn't have to achieve super accurate trajectory, just good enough to see gravitational perturbation.
Not much of a launcher needed for this. It might even work as a ride-along payload. Could be a relatively low-cost way of resolving this weird density result.