Discovery and optical evolution of a new cataclysmic variable in Cygnus

ATel #13345; Simone Leonini, Massimo Conti, Paolo Rosi, Luz Marina Tinjaca Ramirez (Montarrenti Observatory, Siena - Italy), Giacomo Bonnoli, Alessandro Marchini, Eleonora Bernardi, Leonella Filippa Saya (Astronomical Observatory, Department of Physical Sciences, Earth and Enviromment, University of Siena - Italy)
on 11 Dec 2019; 17:46 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Giacomo Bonnoli (giacomo.bonnoli@unisi.it)

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We report the discovery of the optical transient AT 2019vww. The source was observed in the field of the UGC11775 galaxy on Nov 30.716 and is located at the position: R.A.=21 35 45.54 +/- 0.17 Dec= +35 21 53.5 +/-0.20 (J2000.0); astrometry is based on the UCAC-4 catalogue. Observation was carried on from Montarrenti Observatory, Siena, Italy (C88), in the framework of the Italian Supernovae Search Project and using a 0.53 m f/8.7 Ritchey-Chretien telescope equipped with an Apogee Alta U47 CCD camera. The scientific image was obtained without filter and we measured the source at mag 16.92 (0.03) in the CV filter; photometry was performed by means of the MaximDL software package, selecting reference and check stars in the field of view from the APASS9 catalogue (Henden et al., 2016).

On Dec 01 an optical spectrum (R~130) was obtained by Robin Leadbeater using the modified ALPY spectrograph at Three Hills Observatory. The spectrum shows a blue continuum and H alpha emission at zero redshift, in agreement with the interpretation of the transient as a cataclysmic variable in our galaxy, of undetermined type. We thank Robin Leadbeater for performing and analyzing promptly the follow-up observation and for proposing the preliminary classification of the transient.

We observed again AT 2019vww on Dec 03.721 and we measured the source at mag 15.31 (0.01), then we asked the Astronomical Observatory of the University of Siena for collaboration to monitor the transient. Observations from the Siena Observatory were carried on using a 0.3 m f/5.6 Maksutov-Cassegrain telescope, a Sbig STL-6303 CCD camera and V photometric filter (Johnson-Cousins).

Our measurements are summarized in the following table:

Civil Date (UT) Filter mag (dmag) Observatory
2019 Oct 22.854 CV >19.5 (-) Montarrenti
2019 Nov 30.716 CV 16.92 (0.03) Montarrenti
2019 Dec 03.721 CV 15.31 (0.01) Montarrenti
2019 Dec 03.810 V 15.34 (0.01) Siena Univ.
2019 Dec 03.813 R 15.22 (0.01) Siena Univ.
2019 Dec 04.740 CV 15.58 (0.01) Montarrenti
2019 Dec 04.770 V 15.56 (0.03) Siena Univ.
2019 Dec 04.774 R 15.49 (0.04) Siena Univ.
2019 Dec 08.766 CV 16.29 (0.01) Montarrenti
2019 Dec 10.705 V 16.47 (0.03) Univ. Siena


Archival observations of the same field obtained at the Montarrenti Observatory do not shown any stellar source at that position down to limit magnitudes CV ~19.0-19.5. No source is reported in the AAVSO VSX database either.

We will continue monitoring the evolution of AT 2019vww in the following nights. Follow-up observations are encouraged in order to determine the class of the cataclysmic variable.

The observations from the Astronomical Observatory of the University of Siena were performed in the context of a guidance project about astrophysics involving high school students from the "Liceo A. Poliziano" (Montepulciano) and the "Liceo A. Volta" (Colle Val d'Elsa). We thank all of them for their enthusiastic participation in the observations and photometric analyses performed along their guidance project: A. Alfieri, E. Avanzati, A. Avignonesi, L. Beligni, A. Bologni, M. Brandi, L. Bufalini, F. Camisa, A. Cardelli, B. Carletti, V. Casasole, M. Cerini, F. Civitelli, C. Del Secco, E. Dringoli, A. Duchini, A. Falcone, F. Fè, A. Giomarelli, G. Gorelli, D. Laur, N. Mencarelli, G. Mesina, G. Nanni, C.A. Nocchi, G. Palazzoni, E. Paulet, L. Pierguidi, E. Pucci, N. Redi, G. Salutari, J.P. Savino, L. Stefanucci, F. Trabalzini, T. Trabalzini, N. Viviani (Liceo "Poliziano"); T. Cappelli, G. Leoncini (Liceo "A. Volta"). Co-authors Eleonora Bernardi and Leonella Filippa Saya contributed to this project within the framework of their training program as undergraduate students in Physics at the University of Siena.

Transient AT 2019vww