  The WD 1145+017 system shows irregular transit features that are consistent
with the tidal disruption of differentiated asteroids with bulk densities $< 4$
g cm$^{-3}$ and bulk masses $\lesssim 10^{21}$ kg (Veras et al., 2017;
arXiv:1610.06926). We use the open-source N-body code REBOUND (Rein and Liu,
2011; arXiv:1110.4876) to simulate this disruption with different internal
structures: varying the core volume fraction, mantle/core density ratio, and
the presence/absence of a thin low-density crust. We allow the rubble pile to
partially disrupt and capture lightcurves at a specific point during the
disruption at cadences comparable to those from ground-based photometry. As a
proof-of-concept we show that varying these structural parameters have
observationally distinguishable effects on the transit light curve as the
asteroid is disrupted and compare the simulation-generated lightcurves to data
from Gary et al., 2017 (arXiv:1608.00026). With the caveat that our simulations
do not model the sublimation in detail or account for its effects on orbital
evolution, we find that a low core fraction and low mantle/core density ratio
asteroid is most consistent with the stable transit feature present for
multiple weeks circa April 2016 (referred to as G6121 in Gary et al., 2017
(arXiv:1608.00026) and A1 in Hallakoun et al., 2017 (arXiv:1702.05483).
Connecting tidal disruption simulations to photometry suggests characteristics
for the interior structure and composition of an exoplanetary body, information
that is only possible because we are observing the death of the planetary
system in action. All-sky survey missions such as TESS and LSST will be able to
detect other systems like WD 1145+017, creating a sample of subjects for a new
subfield of planetary science: necroplanetology.
