We present the results of a 63 ks Chandra observation of the “ supernova impostor ” SN 2010da four months after it was first observed on 25 May 2010 .
We detect an X-ray source at \sim 7 \sigma confidence coincident with the optical location of the SN 2010da outburst .
Our imaging analysis has revealed a hard central point source , surrounded by soft diffuse emission extending as far as \sim 8 ^ { \prime \prime } north of the central source .
The diffuse emission has a hardness ratio , 0.35-2 keV luminosity ( \sim 6 \times 10 ^ { 35 } erg s ^ { -1 } ) , and size ( \sim 20 pc ) consistent with that of a supernova remnant , although the low number of counts prohibits detailed spectral modeling .
Our best-fit spectral model for the hard central source is a black body ( kT = 1.79 ^ { +0.66 } _ { -0.43 } keV ) with no evidence for intrinsic absorption beyond the Galactic column .
We estimate the 0.3-10 keV luminosity to be 1.7 ^ { +0.2 } _ { -0.5 } \times 10 ^ { 37 } erg s ^ { -1 } , a factor of \sim 25 decrease since the initial outburst four months previously .
The high X-ray luminosity and slow fading rate is not consistent with this object being a single massive star undergoing an outburst ; instead , we favor the scenario where the massive star powering the SN 2010da optical transient is part of a wind-fed supergiant X-ray binary system with a compact companion powering the observed X-ray emission .