The potential of VLTI observations for the study of circumstellar disk variability

TL;DR

This study explores how high-resolution VLTI interferometric observations can detect and analyze variability in young stellar objects caused by changes in their accretion processes, using simulations and a web tool.

Contribution

It introduces a simulation-based analysis of interferometric variability in young stars and provides a web application for customized impact estimation.

Findings

Accretion luminosity variations cause significant interferometric observable changes.

Interferometric data can help understand physical processes in variable young stellar objects.

The VLTI B-VAR web app enables tailored impact assessments for observations.

Abstract

Context. A characteristic feature of young stellar objects is their variability, which is caused by a variety of different physical processes. High-resolution interferometric observations in the near- and mid-infrared wavelength ranges spanning multiple epochs allow the detailed study of these processes. Aims. We aim at investigating the expected variations of the interferometric observables connected to changes in the measured photometric fluxes of a typical variable accreting central young stellar object with a circumstellar disk. Methods. We calculated visibilities and closure phases as well as the photometric flux of brightness distributions obtained using 3D Monte Carlo radiative transfer simulations for a model of a circumstellar disk with an accreting central star. Results. Changes in the accretion luminosity of the central object, that is, an accreting pre-main-sequence star, can lead to significant variations in the visibility and closure phase of the star-disk system measured with instruments at the Very Large Telescope Interferometer (VLTI) that can be related to changes in the photometric flux. Taking into account additional effects due to baseline variation, interferometric observations can provide valuable contributions to the understanding of the underlying processes. Additionally, we provide the web application VLTI B-VAR that allows the impact of the hour angle on the visibility and closure phase for customized intensity maps to be estimated.