Abstract
The V838 Mon's behavior and the nature of the progenitor object are not well understood. Type B stars recently have been found in the vicinity of V838 Mon and it is thought that they may be part of a young open cluster. Since the cluster is in a spiral arm of the Galaxy, the identification of additional member stars is complicated; therefore, photometric and spectroscopic studies are necessary. We present the preliminary results of our photometric analyses with images obtained from the Advanced Camera for Surveys (ACS) on Hubble Space Telescope (HST).
