HSC16aayt: Slowly evolving interacting transient rising for more than
  100 days
  We report our observations of HSC16aayt (SN 2016jiu), which was discovered by
the Subaru/Hyper Suprime-Cam (HSC) transient survey conducted as part of Subaru
Strategic Program (SSP). It shows very slow photometric evolution and its rise
time is more than 100 days. The optical magnitude change in 400 days remains
within 0.6 mag. Spectra of HSC16aayt show a strong narrow emission line and we
classify it as a Type IIn supernova. The redshift of HSC16aayt is 0.6814 +/-
0.0002 from the spectra. Its host galaxy center is at 5 kpc from the supernova
location and HSC16aayt might be another example of isolated Type IIn
supernovae, although the possible existence of underlying star forming activity
of the host galaxy at the supernova location is not excluded.
