Changing looks of the nucleus of Seyfert galaxy NGC 3516 during
  2016-2020
  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 Hbeta 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 H${\beta}$
again was weakened and was practically not observed, remaining as weak until
the end of 2019. At the end of 2019, the broad component Hbeta 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.
