2025A&A...704A.229F

Disk warps and accretion hot spots may leave their imprint on photometric light curves and spectra of TTauri stars. We disentangle accretion and extinction signatures for the V505 Ori system using photometry in the B, V, R, and I bands taken mainly between November 2019 and November 2024, three ESO VLT/UVES spectra from November and December 2020, and two ESO/X-Shooter spectra taken in February and December 2020. V505 Ori has tentatively been classified as an AA Tau-like dipper based on photometric light curves. With the three UVES spectra and one X-Shooter spectrum taken from one brightness maximum to the next minimum, we find decreasing veiling with r₅₀₀=2.22 ± 0.29 to 1.06 ± 0.32 and increasing reddening from A_V=0.0 to 0.85 mag from maximum to minimum (optical) brightness. From the spectra we also report accretion features around the brightness maximum that contrast with the behaviour of AA Tau-like dippers, which show such features at the brightness minimum. For V505 Ori we therefore propose a scenario with a hot circumpolar accretion spot in combination with a more severe occultation by the stellar disk at brightness minimum. From photometric and spectral model fitting, we infer accretion spot sizes of about 10-20% at the brightness maximum down to 5% at the brightness minimum. Moreover, the spectral model fitting allows us to estimate that up to about 80% of the stellar light is blocked by the disk, while about 50% down to 10% of the stellar disk light is subject to reddening as its line of sight passes through outer layers of the disk. Moreover, there must be long-term variability of the accretion flow, as evidenced by the X-Shooter spectrum taken 10 months earlier.