The nearby, young, isolated, dusty star HD 166191

TL;DR

This study characterizes the young star HD 166191, revealing high infrared excess and dust indicative of recent planetary collisions or formation processes, based on multi-wavelength observations and spectroscopic analysis.

Contribution

It provides detailed observational evidence of a young star with significant dust and infrared excess, suggesting active planet formation or recent collisions.

Findings

High fractional IR luminosity (~10%) indicating substantial dust presence.

Detection of a strong 10 μm solid-state emission feature.

Estimated stellar age between 10-100 million years.

Abstract

We report an in-depth study of the F8-type star HD 166191, identified in an ongoing survey for stars exhibiting infrared emission above their expected photospheres in the Wide-field Infrared Survey Explorer all-sky catalog. The fractional IR luminosity measured from 3.5 to 70 $\mu$m is exceptionally high (L$_{IR}$/L$_{bol}$ $\sim$10%). Near-diffraction limited imaging observations with the T-ReCS Si filter set on the Gemini South telescope and adaptive optics imaging with the NIRC2 Lp filter on the Keck II telescope confirmed that the excess emission coincides with the star. Si-band images show a strong solid-state emission feature at $\sim$10 $\mu$m. Theoretical evolutionary isochrones and optical spectroscopic observations indicate a stellar age in the range 10-100 Myr. The large dust mass seen in HD 166191's terrestrial planet zone is indicative of a recent collision between planetary embryos or massive ongoing collisional grinding associated with planet building.