[vsnet-outburst 26027] MASTER OT J172758.09+380021.5 outburst

[Taichi Kato]

MASTER OT J172758.09+380021.5 outburst

   According to the ZTF data, this object is not an ordinary
SU UMa star (see vsnet-alert 23720, 24112).

2018 Mar-Apr. superoutburst: two post-superoutburst rebrightenings
   and a slow fading tail like a WZ Sge star.
2018 July-Aug. superoutburst: deep dip in the middle of
   a superoutburst.
2019 Jan.-Feb: long rebrightening.

   Currently, the supercycle appears to be ~70 d.

   Thorstensen's spectrum did not show enhanced helium lines.
This object probably needs to be studied in detail.
(Could it be a WZ Sge star mimic or EI Psc-type object?)

  YYYYMMDD(UT)   mag  observer
  20201023.1179 17.890zr  (Zwicky Transient Facility Lasair (Masci+ 2019))
  20201028.1181 17.977zr  (Zwicky Transient Facility Lasair (Masci+ 2019))
  20201101.1589 16.600zr  (Zwicky Transient Facility Lasair (Masci+ 2019))
  20201104.0811 18.009zr  (Zwicky Transient Facility Lasair (Masci+ 2019))
  20201111.1389 14.521zr  (Zwicky Transient Facility Lasair (Masci+ 2019))