  The recently discovered first interstellar object 1I/2017 U1 (`Oumuamua) has
brightness that varies by a factor of 10, a range greater than that of any
Solar System asteroid, a spectrum characteristic of Type D asteroids, and no
evidence of evaporating volatiles, contrary to expectation for exo-Oort clouds.
This object was the first example of the proposed "Jurads", objects depleted in
volatiles and ejected from planetary systems during the post-main sequence
evolution of their parent star. I suggest that heating by the star's giant
stage fluidized a precursor cometary object as volatiles escaped, causing it to
assume the Jacobi ellipsoidal shape of a self-gravitating incompressible
liquid. The collision that produced the inferred tumbling motion must have
occurred thousands of years after the formation of 1I/2017 U1 `Oumuamua. Jacobi
ellipsoids have a unique relation among rotation rate, density and axial ratio.
The inferred axial ratio $\gtrapprox 5$ implies a lower bound on the density of
1.6 g/cm$^3$, excluding an icy interior unless it is almost entirely frozen
CO$_2$. This object is the first Jurad to be discovered and may be related to
accreting objects that pollute white dwarf atmospheres and may make Soft Gamma
Repeaters.
