Comprehensive analysis of HD 105, a young Solar System analog


Abstract in English

HD~105 is a nearby, pre-main sequence G0 star hosting a moderately bright debris disc ($L_{rm dust}/L_{star} sim 2.6times10^{-4}$). HD~105 and its surroundings might therefore be considered an analogue of the young Solar System. We refine the stellar parameters based on an improved Gaia parallax distance, identify it as a pre-main sequence star {with an age of 50~$pm$~16~Myr}. The circumstellar disc was marginally resolved by textit{Herschel}/PACS imaging at far-infrared wavelengths. Here we present an archival ALMA observation at 1.3~mm, revealing the extent and orientation of the disc. We also present textit{HST}/NICMOS and VLT/SPHERE near-infrared images, where we recover the disc in scattered light at the $geq$~5-$sigma$ level. This was achieved by employing a novel annular averaging technique, and is the first time this has been achieved for a disc in scattered light. Simultaneous modelling of the available photometry, disc architecture, and detection in scattered light allow better determination of the discs architecture, and dust grain minimum size, composition, and albedo. We measure the dust albedo to lie between 0.19 and 0.06, the lower value being consistent with Edgeworth-Kuiper belt objects.

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