Spectroscopic classification of transient AT2019qcf as a cataclysmic variable
ATel #13117; Marco Berton (FINCA, Metsahovi Radio Observatory, Finland), Elina Lindfors (FINCA, University of Turku, Finland), Alexander Kurtenkov (Institute of Astronomy and NAO, BAS, Bulgaria), Jose Feliciano Agui Fernandez (Instituto de Astrofisica de Andalucia, Spain), Sarah Casura (Universitaet Hamburg, Germany), Olga I. Mikhalchenko (V. N. Karazin Kharkiv National University, Ukraine), Jake A. Mitchell (Durham University, UK), Armin Nabizadeh (University of Turku, Finland), Irham Taufik Andika (Max Planck Institute for Astronomy, Germany), Sofia Ventura (University of Siena, Italy), Ilaria Viale (University of Genova, Italy), Heidi Korhonen (DARK/NBI, Denmark)
on 18 Sep 2019; 22:08 UT
Credential Certification: Marco Berton (marco.berton@utu.fi)
Subjects: Optical, Cataclysmic Variable, Transient
We have obtained a low resolution flux-calibrated spectrum of the transient AT2019qcf (ZTF19abyrano/ATLAS19vbk) with the Rozhen 2m Ritchey-Chretien telescope during the 2019 OPTICON NEON School at the Bulgarian National Astronomical Observatory. The spectrum (coverage 5000-9000 A) was obtained with the 2-channel Focal Reducer Rozhen (FoReRo2), equipped with a 300-lines/mm grism and a resolution of 0.3 nm/px. We observed it on 2019-09-17 at UT 21:06 in a single 600 seconds exposure. It was calibrated using He and Ne arc lamps and the spectrophotometric standard star BD+174708.
The spectrum is a blue, almost featureless, power law continuum with a slope alpha ~ -3.1 (F proportional to wavelength^alpha), in which we detect the Halpha line in absorption at z = 0. No emission line is detected, probably because of the poor signal-to-noise. Because of these properties, we classify AT2019qcf as a typical cataclysmic variable in outburst. It is worth mentioning that the source had a previous detection in PanSTARRS 1 with r=18.3 mag.
