Mid-IR spectra of HD 142527 inner disc and common dust types

Mid-IR spectrum of the inner region of the protoplanetary disc around the young star HD 142527, as observed with the MIDI instrument at the VLT Interferometer (upper). Below it are shown laboratory spectra of two crystalline minerals as well as of an Interplanetary Dust Particle (IDP; captured in the Earth's upper atmosphere) with hydrated silicates and, at the bottom, a typical telescopic spectrum of dust grains in the interstellar space. The spectral "signatures" of crystalline pyroxene and olivine, i.e. peaks at wavelength 9.2 and 11.3 µm, respectively, are clearly visible in the spectrum of the inner stellar disc, demonstrating the presence of these species in that region of the disc.