Special issues No. 2,
Pages: 63,
https://doi.org/10.69646/15scslsa38
XV Serbian Conference on Spectral Line Shapes in Astrophysics
Published by: Astronomical Observatory Belgrade

The Seyfert galaxy NGC 3516 has undergone major spectral changes in the past years. Here, we present long term spectropolarimetric variability in optical band. Archival polarimetric data that are publicly available cover 6 epochs from 1975-1996. Two decades later, we have obtained high-quality spectropolarimetric data using NOT ALFOSC and SAO BTA instruments over 6 epochs from 2017-2021 when the system was in a quiet state, until a flare-burst occurred in early 2021. We find that the degree of polarization rotates by ∼90◦ with the onset of the change in 1993. Simultaneously, polarization degree drops from ∼0.5-0.7% to ∼0.3% we obtained recently.