  Recent numerical simulations in general relativistic magnetohydrodynamics
(GRMHD) provide useful constraints for the interpretation of the GW170817
discovery. Combining the observed data with these simulations leads to a bound
on the maximum mass of a cold, spherical neutron star (the TOV limit): ${M_{\rm
max}^{\rm sph}}\lesssim 2.74/\beta$, where $\beta$ is the ratio of the maximum
mass of a uniformly rotating neutron star (the supramassive limit) over the
maximum mass of a nonrotating star. Causality arguments allow $\beta$ to be as
high as $1.27$, while most realistic candidate equations of state predict
$\beta$ to be closer to $1.2$, yielding ${M_{\rm max}^{\rm sph}}$ in the range
$2.16-2.28 M_\odot$. A minimal set of assumptions based on these simulations
distinguishes this analysis from previous ones, but leads to a similar
estimate. There are caveats, however, and they are enumerated and discussed.
The caveats can be removed by further simulations and analysis to firm up the
basic argument.
