2012ApJ...753L..38B

With the uniquely high contrast within 0".1 (Δmag(L') = 5-6.5 mag) available using Sparse Aperture Masking with NACO at Very Large Telescope, we detected asymmetry in the flux from the Herbig Fe star HD 142527 with a barycenter emission situated at a projected separation of 88±5 mas (12.8 ±1.5 AU at 145 pc) and flux ratios in H, K, and L' of 0.016±0.007, 0.012 ±0.008, and 0.0086±0.0011, respectively (3σ errors), relative to the primary star and disk. After extensive closure-phase modeling, we interpret this detection as a close-in, low-mass stellar companion with an estimated mass of ∼0.1-0.4 M_☉. HD 142527 has a complex disk structure, with an inner gap imaged in both the near and mid-IR as well as a spiral feature in the outer disk in the near-IR. This newly detected low-mass stellar companion may provide a critical explanation of the observed disk structure.