Spectral Classification of the transient PNV J00494338+4033383 = AT 2020abjr = ZTF18abxzyss as NOT a nova in M31 but a dwarf nova
ATel #14266; Kenta Taguchi, Yusuke Tampo, Keisuke Isogai, Naoto Kojiguchi, Riko Shimizu, Yosuke Alexandre Yamashiki (Kyoto University)
on 14 Dec 2020; 17:07 UT
Credential Certification: Keisuke Isogai (isogai@kusastro.kyoto-u.ac.jp)
Subjects: Cataclysmic Variable, Nova, Transient, Variables
We report on a spectrum of the transient PNV J00494388+4033383 = AT 2020abjr = ZTF18abxzyss. We obtained the spectrum from 2020-12-02.60 to 2020-12-02.64 UT by using a fiber-fed integral field spectrograph (KOOLS-IFU; Matsubayashi et al. 2019) mounted on the 3.8-m telescope Seimei at Okayama Observatory of Kyoto University.
As reported to CBAT and TNS, this object was discovered by XOSS at V=18.1 mag on 2020-12-02.51 and reported as a "possible nova in M31". It was not detected at 2020-12-02.28 by ZTF (the typical limiting mag is 20--21 mag). Then, this object faded to g = 19.4 at 2020-12-12.17 and r = 19.5 at 2020-12-12.22. According to ZTF, a past outburst was detected on 2018-09-21. Moreover, another outburst was detected by Pan-STARRS1 at r = 18.2 on 2013-10-16.43.
Our spectrum shows only a blue continuum and no prominent lines.
The fading rate of about 0.1 mag/d in the ZTF data is also consistent with those in dwarf nova outbursts. These features favor this object as a dwarf nova in Milky Way, not a nova in M31.
Our Spectrum
