Spectroscopic classification of AT2020idu = ZTF20aavnpug = Gaia20byj as a dwarf nova
ATel #13680; Keisuke Isogai (Kyoto University, Okayama Observatory), Hiroyuki Maehara (National Astronomical Observatory of Japan)
on 28 Apr 2020; 19:52 UT
Credential Certification: Keisuke Isogai (isogai@kusastro.kyoto-u.ac.jp)
Subjects: Optical, Cataclysmic Variable, Transient, Variables
I report on a spectrum of the optical transient AT2020idu = ZTF20aavnpug = Gaia20byj obtained on 2020-4-28.70 UT by using a fiber-fed integral field spectrograph (KOOLS-IFU; Matsubayashi et al. 2019) mounted on the 3.8-m telescope Seimei of Kyoto University.
This object was discovered by ZTF at r=16.95 mag on 2020-04-22.46 UT and reported to TNS as a supernova candidate. Then, Gaia reported the maximum brightness of 15.32 mag.
My spectrum shows a blue continuum with an H alpha emission and no other clear features. Thus, this object can be classified as a dwarf nova. Because there is no optical counterpart in Pan-STARRS1, the outburst amplitude is larger than 6 mag. So this object will be a SU UMa or WZ Sge-type dwarf nova.
Spectrum of AT2020idu
