Characterization of the low-mass companion HD 142527 B

The circumstellar disk of the Herbig Fe star HD 142527 is host to several remarkable features including a warped inner disk, a 120 au-wide annular gap, a prominent dust trap and several spiral arms. A low-mass companion, HD 142527 B, was also found orbiting the primary star at only ~14 au. This poster presents how we managed to better characterize this companion using VLT/SINFONI in pupil-tracking mode. Using ADI-based post-processing algorithms, we conspicuously re-detected the companion in most spectral channels, enabling us to extract the first medium-resolution spectrum of a low-mass companion within 0.1'' from its central star. Our analysis suggests that HD 142527 B is an M2.5+-1.0 star with an effective temperature of 3500+-100 K, possibly surrounded with a hot (1700 K) inner rim. Based on its location in HR diagrams compared to stellar evolution tracks, we constrain the mass and age to be 0.34+-0.06 MSun and 0.5--3.0 Myr, respectively. The new spectral type makes HD 142527 B a twin of the well known TW Hya T-Tauri star, and new hydro-dynamical simulations considering our revised mass of HD 142527 B show that companion-disk interactions alone are able to account qualitatively for the observed morphology of the disk.