2020ApJ...900..195I

We have made a spectroscopic investigation of the nature of 053949.17-693747.4, a blue star with mid-infrared excess, projected within a superbubble in the H II complex N160 in the Large Magellanic Cloud (LMC). Analyses of photometric and spectrophotometric data of this star indicate that it is an O7 ± 1 V in the LMC. The radial velocity of this star from a 2010 spectrum shows an offset of ∼150 km s^–1 from that of the background interstellar medium (ISM), while the spectra taken in 2020 show stellar velocity similar to the ISM velocity. The velocity variations indicate that 053949.17-693747.4 must be a binary system. The lack of spectroscopic features from a stellar companion and the large radial velocity variations of the primary O7 star imply that the companion is most likely an early-type B star. Hubble Space Telescope Hα and [O III] images of 053949.17-693747.4 show a small nebula around the star with the southern rim resembling a blow-shock-like structure. While the physical nature as a bow shock cannot be robustly established, this small nebula is likely the cause of 053949.17-693747.4's mid-infrared excess. Spectroscopic monitoring over an entire binary period is needed to establish the period and systemic velocity to determine the properties of the binary companion and whether this binary system is a runaway.