Spectroscopic observation of the superoutburst from HP Cet (ZTF19abydbvw) dwarf nova
ATel #13183; Monika Soraisam (NCSA/UIUC), Rafael Nunez, Kevin McKinnon (UCSC), Chien-Hsiu Lee (NSF OIR Lab), Puragra Guhathakurta (UCSC), Paula Szkody (UW), Thomas Matheson, Abhijit Saha (NSF OIR Lab)
on 11 Oct 2019; 18:47 UT
Credential Certification: Monika Soraisam (soraisam@noao.edu)
Subjects: Optical, Cataclysmic Variable, Transient
We report the spectroscopic observation of ZTF19abydbvw (HP Cet). This object is a WZ Sge-type dwarf nova candidate, originally discovered by Szkody et al. (2002). Its superoutburst has recently been detected from the public alert stream of ZTF by a customized filter on the ANTARES alert-broker (https://antares.noao.edu/). This current outburst has also been reported in CBAT (http://www.cbat.eps.harvard.edu/unconf/followups/J02332248+0051018.html).
Name | RA (J2000) | Dec (J2000) | Galactic l (deg) | Galactic b (deg) | First detection: MJD, mag
ZTF19abydbvw (HP Cet) | 2:33:22.62 | 0:50:59.28 | 168.297 | -52.801 | 58735.439375, g~17.04+/-0.03
On 2019 October 9 UT, we obtained the spectrum of this source with the Kast double spectrograph on the Shane 3 m telescope at Lick Observatory. It shows a blue continuum with Balmer lines in emission. We compared this spectrum with that obtained recently by SDSS in 2013, during the source's quiescent phase. We find the present continuum to be much stronger and the Balmer lines much weaker in strength than those in the quiescent-stage. This is typical for a dwarf nova outburst during its decline.
All this evidence is in line with the current outburst indeed being a dwarf nova.
The light curve of ZTF19abydbvw can be accessed at https://antares.noao.edu/alerts/locus/5328410.
