Spectroscopic classification of the ultra-short period dwarf nova MASTER OT J234843.23+250250.4
ATel #13277; Keisuke Isogai, Miho Kawabata (Kyoto University, Okayama Observatory), Keiichi Maeda (Kyoto University)
on 7 Nov 2019; 07:23 UT
Credential Certification: Keisuke Isogai (isogai@kusastro.kyoto-u.ac.jp)
Subjects: Optical, Cataclysmic Variable, Transient, Variables
We report on a low-resolution spectrum of the ultra-short period dwarf nova MASTER OT J234843.23+250250.4.
The previous superoutburst of this object was detected in 2013, then
Kato et al. (2014)
reported that the superhump period is only 0.034 d.
Thus, this object had been a good candidate for an AM CVn-type (helium-rich) object.
According to the report by Patrick Schmeer ,
the present outburst has started on Nov. 1.
We obtained a low-resolution spectrum on 2019-11-05.62 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.
The spectrum shows a blue continuum with Hβ and γ absorption lines.
On the other hand, there are no definite signals of helium lines.
Thus, we concluded that this object is an EI Psc-type object, which is a hydrogen-rich dwarf nova below the period minimum, rather than an AM CVn-type one.
Spectrum of MASTER OT J234843.23+250250.4
