Dust evolution in the circumstellar disc of the unclassified B[e] star HD 50138

Abstract

We studied the disc of the unclassified B[e] star HD 50138, in order to explore its structure, and to find indications for the evolutionary status of this system, whether it is a young Herbig Be or a post-main-sequence star. Using high spatial resolution interferometric measurements from MIDI instrument (N-band) on the Very Large Telescope Interferometer, we analysed the disc size, the time-variability of the disc's thermal emission, and the spectral shape of the $10\mu$m silicate feature. By fitting simple disc models, we determined the inclination and the mid-infrared size of the disc, confirming earlier results based on a lower number of observations. We searched for mid-infrared temporal variability of different regions of the disc, and concluded that its morphology is not experiencing significant changes over the observed epochs. We characterized the mid-infrared silicate feature by determining the feature amplitude and the $11.3/9.8\mu$m flux ratio. The latter parameter is a good indicator of the grain size. The shape of the feature suggests the presence of crystalline silicate grains in the disc. The interferometric data revealed a strong radial trend in the mineralogy: while the disc's innermost region seems to be dominated by forsterite grains, at intermediate radii both forsterite and enstatite may be present. The outer disc may predominantly contain amorphous silicate particles. A comparison of the observed spectral shape with that of a sample of intermediate-mass stars (supergiants, Herbig Ae/Be stars, unclassified B[e] stars) implied that the evolutionary state of HD 50138 cannot be unambiguously decided from mid-IR spectroscopy.

arXiv comment13 pages, 7 figures, to be published in MNRAS

References in corpus (41)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• The absence of crystalline silicates in the diffuse interstellar medium
• A 10 micron spectroscopic survey of Herbig Ae star disks: grain growth and crystallization
• The inner regions of protoplanetary disks
• Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk
• The ASAS-SN Catalog of Variable Stars II: Uniform Classification of 412,000 Known Variables
• The origin of crystalline silicates in the Herbig Be star HD100546 and in comet Hale-Bopp
• Annealing of Silicate Dust by Nebular Shocks at 10 AU
• Dust evolution in protoplanetary disks around Herbig Ae/Be stars - The Spitzer view
• Structure of Herbig AeBe disks at the milliarcsecond scale A statistical survey in the H band using PIONIER-VLTI
• On the binarity of Herbig Ae/Be stars
• On the structure of the transition disk around TW Hya
• Evidence for grain growth in T Tauri disks
• Dust Transport in Protostellar Disks Through Turbulence and Settling
• The complex morphology of the young disk MWC 758: Spirals and dust clumps around a large cavity
• CASSIS: The Cornell Atlas of Spitzer/Infrared Spectrograph Sources. II. High-resolution observations
• Strong near-infrared emission in the sub-AU disk of the Herbig Ae star HD163296: evidence for refractory dust?
• The structure of disks around intermediate-mass young stars from mid-infrared interferometry. Evidence for a population of group II disks with gaps
• Spiral Arms in Disks: Planets or Gravitational Instability?
• An Observational Perspective of Transitional Disks
• Dust Coagulation and Settling in Layered Protoplanetary Disks
• Mid-infrared size survey of Young Stellar Objects: Description of Keck segment-tilting experiment and basic results
• Planet-driven spiral arms in protoplanetary disks: II. Implications
• The pseudo-photosphere model for the continuum emission of gaseous discs
• The Orbit of the Companion to HD 100453A: Binary-Driven Spiral Arms in a Protoplanetary Disk
• The galactic unclassified B[e] star HD 50138. II. Interferometric constraints on the close circumstellar environment
• VLTI/MIDI atlas of disks around low- and intermediate-mass young stellar objects
• The galactic unclassified B[e] star HD 50138. I. A possible new shell phase
• Inhomogeneous molecular ring around the B[e] supergiant LHA 120-S 73
• A disk asymmetry in motion around the B[e] star MWC158
• A resolved, au-scale gas disk around the B[e] star HD 50138
• Location and sizes of forsterite grains in protoplanetary disks: interpretation from the Herschel DIGIT programme
• First detections of FS Canis Majoris stars in clusters. Evolutionary state as constrained by coeval massive stars
• On the Silicate Crystallinities of Oxygen-Rich Evolved Stars and Their Mass Loss Rates
• Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon III. HD 50138
• The galactic unclassified B[e] star HD 50138 III. The short-term line profile variability of its photospheric lines
• Evolutionary status of isolated B[e] stars
• The circumstellar environment of HD50138 revealed by VLTI/AMBER at high angular resolution
• Velocity resolved [O I] 63 $\mu$m emission in the HD 50138 circumstellar disk

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