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We present first results from a high resolution multi-band survey of theWesterlund 2 region with the Hubble Space Telescope. Specifically, we imagedWesterlund 2 with the Advanced Camera for Surveys through the $F555W$, $F814W$,and $F658N$ filters and with the Wide Field Camera 3 in the $F125W$, $F160W$,and $F128N$ filters. We derive the first high resolution pixel-to-pixel map ofthe color excess $E(B-V)_g$ of the gas associated with the cluster, combiningthe H$\alpha$ ($F658N$) and Pa$\beta$ ($F128N$) line observations. Wedemonstrate that, as expected, the region is affected by significantdifferential reddening with a median of $E(B-V)_g=1.87$~mag. After separatingthe populations of cluster members and foreground contaminants using a$(F814W-F160W)$ vs. $F814W$ color-magnitude diagram, we identify a pronouncedpre-main-sequence population in Westerlund 2 showing a distinct turn-on. Afterdereddening each star of Westerlund 2 individually in the color-magnitudediagram we find via over-plotting PARSEC isochrones that the distance is ingood agreement with the literature value of $\sim4.16 \pm 0.33$~kpc. Withzero-age-main-sequence fitting to two-color-diagrams, we derive a value oftotal to selective extinction of $R_V=3.95 \pm 0.135$. A spatial density map ofthe stellar content reveals that the cluster might be composed of two clumps.We estimate the same age of 0.5-2.0 Myr for both clumps. While the two clumpsappear to be coeval, the northern clump shows a $\sim 20 \%$ lower stellarsurface density.

A High-Resolution Multiband Survey of Westerlund 2 With the Hubble Space Telescope I: Is the Massive Star Cluster Double?