Photometric signatures of magnetospheric star-disk interaction in different accretion regimes
Year: 2025
Type: article
Abstract: The interaction with the magnetic field of the protostar is the main mechanism that controls the circumstellar disk dynamics in its innermost regions. By channeling the disk accretion flow into funnels impacting the stellar surface and triggering different classes of outflows (stellar winds and magnetospheric ejections), the star-disk interaction (SDI) is believed to have a strong impact on the spectral and photometric variability of young forming stars such as classical TTauris. It is widely accepted that magnetospheric accretion can occur in different regimes: (a) stable, where accretion follows two curtains that form opposite spots on the stellar surface, (b) unstable, where different tongues of plasma can penetrate the stellar magnetosphere due to the development of an interchange instability and (c) propeller, a stable regime where the accretion flow is hampered and modulated by the stellar centrifugal barrier triggering more prominent magnetospheric ejections. Using the outcome of several three-dimensional simulations of magnetospheric SDI, we extract synthetic light curves to understand if it is possible to use photometry to infer the accretion regime. To characterize the light curves, we apply different diagnostics, a periodicity metric (Cody et al. 2014), the periodogram analysis and an aperiodic metric (Findeisen et al. 2015). Since we also found that the accretion regime is related to the star-disk angular momentum exchange, we test the possibility of obtaining indications about the spin-up/down state of the protostar from photometric light curves.
Author: Zanni, Claudio
Institution: Osservatorio Astrofisico di Torino
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6893206646
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