2009/04/29 by M. T. Schuster, Michael Schuster, M. Marengo +10 · 1 citation
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/699/2/1423
published as Astrophys.J.699:1423-1432,2009 · Accepted for publication on The Astrophysical Journal
arxiv created 2009/04/29 · openalex publication_date 2009/06/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We present subarcsecond angular resolution, high-Strehl ratio mid-IR adaptive optics images of the powerful OH/IR source and cool hypergiant NML Cyg at 8.8, 9.8, and 11.7 μm. These images reveal once more the complexity in the dusty envelope surrounding this star. We spatially resolve the physical structures (radius ∼ 0 14, ∼240 AU adopting a distance of 1.74 kpc) responsible for NML Cyg's deep 10 μm silicate dust absorption feature. We also detect an asymmetric excess, at separations of ∼0 3–0 5 (∼520–870 AU), northwest from the star. The colors of this excess are consistent with thermal emission of hot, optically thin dust. This excess is oriented in the direction of the Cyg OB2 stellar association, and is likely due to the disruption of NML Cyg's dusty wind with the near-UV radiation flux from the massive hot stars within Cyg OB2. This interaction was predicted in our previous paper to explain the geometry of an inverted photodissociation region observed at optical wavelengths.