Scientifically important discoveries with the help of amateurs I am looking for examples where amateur astronomers in these days contributed sigificantly to important scientifically discoveries.

I am aware of one example: Victor Buso from Argentina was lucky enough to observe a Supernova just when it formed, which has led to follow-up observations by large scientific observatories, and in the end resulted in a Nature article which has Buso as a co-author. 

What might some other similar examples be?



below: "Astronomer Victor Buso poses in front of the telescope with which he witnessed the birth of the supernova 2016gkg. (Victor Buso)" From here, borrowed from Does this amateur observation hold a record even including robotic searches for supernovae?. Click/open for full size.
I guess it depends on what you consider scientifically important, but users at Planet Hunters have helped with the discovery of several exoplanets by analyzing data from the Kepler Space Telescope, as well as the famous Tabby's star (KIC 8462852) which has led to a paper by Tabetha Boyajian co-written by the users who participated in the analysis of the light curve of the star. 

The star is currently still the subject of numerous studies and publications.