  Recently, several groups have resolved a gap that bifurcates planets between
the size of Earth and Neptune into two populations. The location and depth of
this feature is an important signature of the physical processes that form and
sculpt planets. In particular, planets residing in the radius gap are valuable
probes of these processes as they may be undergoing the final stages of
envelope loss. Here, we discuss two views of the radius gap by Fulton &
Petigura (2018; F18) and Van Eylen et al. (2018; V18). In V18, the gap is wider
and more devoid of planets. This is due, in part, to V18's more precise
measurements of planet radius $R_p$. Thanks to Gaia, uncertainties in stellar
radii Rstar are no longer the limiting uncertainties in determining $R_p$ for
the majority of Kepler planets; instead, errors in $R_p/R_\star$ dominate.
V18's analysis incorporated short-cadence photometry along with constraints on
mean stelar density that enabled more accurate determinations of $R_p/R_\star$.
In the F18 analysis, less accurate $R_p/R_\star$ blurs the boundary the radius
gap. The differences in $R_p/R_\star$ are largest at high impact parameter ($b
\gtrsim 0.8$) and often exceed 10%. This motivates excluding high-$b$ planets
from demographic studies, but identifying such planets from long-cadence
photometry alone is challenging. We show that transit duration can serve as an
effective proxy, and we leverage this information to enhance the contrast
between the super-Earth and sub-Neptune populations.
