2013/12/18 by Grant M. Kennedy, G. M. Kennedy, S. J. Murphy +19 · 20 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Context (archaeology) #Debris #Formation and evolution of the Solar System #Geology #Physics #Planet #Planetesimal #Protoplanetary disk #Radiative transfer #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stt2435
published in Monthly Notices of the Royal Astronomical Society 438(4), 3299-3309 (Oxford University Press) · accepted to MNRAS, fixed typos in abstract and axis label
arxiv created 2013/12/18 · openalex publication_date 2014/01/15 · arxiv updated 2014/10/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
HD 166191 has been identified by several studies as hosting a rare and extremely bright warm debris disc with an additional outer cool disc component. However, an alternative interpretation is that the star hosts a disc that is currently in transition between a full gas disc and a largely gas-free debris disc. With the help of new optical to mid-infrared (IR) spectra and Herschel imaging, we argue that the latter interpretation is supported in several ways: (i) we show that HD 166191 is comoving with the ∼4-Myr-old Herbig Ae star HD 163296, suggesting that the two have the same age; (ii) the disc spectrum of HD 166191 is well matched by a standard radiative transfer model of a gaseous protoplanetary disc with an inner hole and (iii) the HD 166191 mid-IR silicate feature is more consistent with similarly primordial objects. We note some potential issues with the debris disc interpretation that should be considered for such extreme objects, whose lifetime at the current brightness is much shorter than the stellar age, or in the case of the outer component requires a mass comparable to the solid component of the solar nebula. These aspects individually and collectively argue that HD 166191 is a 4–5 Myr old star that hosts a gaseous transition disc. Though it does not argue in favour of either scenario, we find strong evidence for 3–5 μm disc variability. We place HD 166191 in context with discs at different evolutionary stages, showing that it is a potentially important object for understanding the protoplanetary to debris disc transition.