DDE 139 outburst YYYYMMDD(UT) mag observer 20210622.2109 20.197zr (Zwicky Transient Facility (Masci et al., 2019)) 20210628.1906 20.372zr (Zwicky Transient Facility (Masci et al., 2019)) 20210704.2402 16.218zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210704.2404 16.218zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210706.2116 17.563zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210706.2118 17.563zg (Zwicky Transient Facility Lasair (Masci+ 2019))