Spectroscopic confirmation of TCP J02191736+2857158 as a WZ Sge-type dwarf nova
ATel #17887; Keisuke Isogai (Kyoto University)
on 12 Jul 2026; 19:38 UT
Credential Certification: Keisuke Isogai (isogai@kusastro.kyoto-u.ac.jp)
Subjects: Optical, Binary, Cataclysmic Variable, Transient, Variables
We report on the spectral features seen in the transient TCP J02191736+2857158.
We obtained the spectrum by using a fiber-fed integral field spectrograph
(KOOLS-IFU; Matsubayashi et al. 2019,
Matsubayashi et al. 2025) attached to one of the Nasmyth focuses of the 3.8-m telescope Seimei at Okayama Observatory of Kyoto University.
According to CBAT, TCP J02191736+2857158 was discovered by the NMW-TexasTech survey at an unfiltered magnitude of 12.5 on 2026-07-12.3618 UT.
According to the PS1 catalog (Chambers+, 2017), there is a possible optical counterpart with g=20.97(3), r=20.88(3), i=20.98((2), and z=20.82(3). Thus, the outburst amplitude seems to be about 8.5 mag.
We obtained an optical spectrum on 2026-07-12.776 UT by using KOOLS-IFU.
The quick look spectrum shows a blue continuum with the Balmer, He I, and He II absorption lines.
The Hα absorption profile also contains a central emission core.
This spectrum and the large amplitude suggest that this object is a new WZ Sge-type dwarf nova.
The spectrum
