Changing looks of the nucleus of Seyfert galaxy NGC 3516 during 2016-2020

Abstract

The results of spectral observations of NGC 3516 with the 2-m telescope of the Shamakhy Astrophysical Observatory during 2016-2020 are presented. In the first half of 2016, the intensive broad component Hβ was found, which indicates a spectral type change compared to 2014, when the broad component was almost invisible. In the second half of 2016, the broad component Hβ again was weakened and was practically not observed, remaining as weak until the end of 2019. At the end of 2019, the broad component Hβ strengthened again, and in May 2020 reached a typical level for the high state of the object. During 2016-2020 we observed several changing looks of NGC 3516.