  We have evidence of X-ray flares in several galaxies consistent with a a star
being tidally disrupted by a supermassive black hole (MBH). If the star starts
on a nearly parabolic orbit relative to the MBH, one can derive that the
fallback rate follows a $t^{-5/3}$ decay. Depending on the penetration factor,
$\beta$, a star will be torn apart differently, and relativistic effects play a
role. We have modified the standard version of the smoothed-particle
hydrodynamics (SPH) code {\sc Gadget} to include a relativistic treatment of
the gravitational forces between the gas particles of a main-sequence (MS) star
and a MBH. We include non-spinning post-Newtonian corrections to incorpore the
periapsis shift and the spin-orbit coupling up to next-to-lowest order. We find
that tidal disruptions around MBHs in the relativistic cases are underluminous
for values starting at $\beta \gtrapprox 2.25$; i.e. the fallback curves
produced in the relativistic cases are progressively lower compared to the
Newtonian simulations as the penetration parameter increases. While the
Newtonian cases display a total disruption, we find that all relativistic
counterparts feature a survival core for penetration factors going to values as
high as $12.05$. We perform a additional dynamical numerical study which shows
that the geodesics of the elements in the star converge at periapsis. We
confirm these findings with an analytical study of the geodesic separation
equation. The luminosity of TDEs must be lower than predicted theoretically due
to the fact that the star will partially survive when relativistic effects are
taken into account. A survival core should consistently emerge from any TDE
with $\beta \gtrapprox 2.25$.
