Confirming new changing--look AGNs discovered through optical
  variability using a random-forest based light curve classifier
  Determining the frequency and duration of changing--look (CL) active galactic
nuclei (AGNs) phenomena, where the optical broad emission lines appear or
disappear, is crucial to understand the evolution of the accretion flow around
supermassive black holes. We present a strategy to select new CL candidates
starting from a spectroscopic type 2 AGNs sample and searching for current type
1 photometric variability. We use the publicly available Zwicky Transient
Facility (ZTF) alert stream and the Automatic Learning for the Rapid
Classification of Events (ALeRCE) light curve classifier to produce a list of
CL candidates with a highly automated algorithm, resulting in 60 candidates.
Visual inspection reduced the sample to 30. We performed new spectroscopic
observations of six candidates of our clean sample, without further refinement,
finding the appearance of clear broad Balmer lines in four of them and
tentative evidence of type changes in the remaining two, which suggests a
promising success rate of $\geq66$ per cent for this CL selection method.
