Spectroscopic classification of Gaia19dum as a reddened nova by using LT/SPRAT

ATel #13070; Pawel Zielinski, Mariusz Gromadzki, Nada Ihanec, Lukasz Wyrzykowski, Katarzyna Kruszynska, Krzysztof Rybicki (Astronomical Observatory, University of Warsaw)
on 3 Sep 2019; 10:46 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Lukasz Wyrzykowski (wyrzykow@astrouw.edu.pl)

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Gaia19dum (aka Dumbledore; AT 2019owg at IAU's Transient Name Server) was detected photometrically on 2019-08-24T21:21:36 UT by Gaia satellite (http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dum/). It was reported as very bright, with Gaia G-band amplitude >8.5 mag, red transient (BP-RP=1.39 mag) located in the Galactic plane (l=64.22851 deg, b=0.32907 deg). The G magnitude when alerting was 13.54. There was no counterpart detected in PanSTARRS survey.

In order to classify the event, we have observed Gaia19dum with 2-m Liverpool Telescope (LT, Steele et al. 2004, Proc. SPIE, vol. 5489, 679) equipped with the Spectrograph for the Rapid Acquisition of Transients (SPRAT, Piascik et al. 2014, Proc. SPIE, vol. 9147, id. 91478H). The spectroscopic observations was gathered on the night 2019-08-30T21:36:29 UT with 200 s exposure time, covering the optical part of electromagnetic window (400-800 nm). The obtained low-resolution spectrum (R=350) best matches a classical nova. There are strong emission lines of Halpha and O I [around 777.3 nm] visible. In addition, other features are clearly observed, e.g., Hbeta line. More details and LT/SPRAT spectrum can be found at: https://wis-tns.weizmann.ac.il/object/2019owg. This result is in agreement with Aydi et al. (2019, ATel#13068).

We encourage to continue the photometric and spectroscopic observations of this bright nova in order to study its light curve and spectral changes in time.

Acknowledgments. We thank LT Support Astronomers for help with observations and data reduction. Observations were carried out under OPTICON programme XOL19B02 (PI: P.Zielinski). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730890. This material reflects only the authors views and the Commission is not liable for any use that may be made of the information contained therein. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. We acknowledge ESA Gaia, DPAC and the Photometric Science Alerts Team (http://gsaweb.ast.cam.ac.uk/alerts)