With the uniquely high contrast within 0.1" (\Delta mag(L') = 5-6.5 magnitudes) available using Sparse Aperture Masking (SAM) with NACO at VLT, 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, 0.0086+/-0.0011 respectively (3-\sigma 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_Sun. 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.
@article{arxiv.1206.2654,
title = {A Likely Close-In Low-Mass Stellar Companion to the Transitional Disk Star HD 142527},
author = {Beth Biller and Sylvestre Lacour and Attila Juhász and Myriam Benisty and Gael Chauvin and Johan Olofsson and Jörg-Uwe Pott and André Müller and Aurora Sicilia-Aguilar and Mickaël Bonnefoy and Peter Tuthill and Philippe Thebault and Thomas Henning and Aurelien Crida},
journal= {arXiv preprint arXiv:1206.2654},
year = {2015}
}