Classification of Gaia16afz as a Dwarf Nova
ATel #8766; L. Schmidtobreick (ESO-Chile), M. Dennefeld (IAP & UPMC, Paris), and the NEON school PhD students E. W. Cori (Univ. Nac. de Ingenieria de Lima, Peru), J. Gschwend (Observ. Nac. de Rio, Brasil), A. Pieres (UFRGS, Porto Alegre, Brasil) and A. Rojas (Univ. Andres Bello, Santiago, Chile)
on 3 Mar 2016; 19:35 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Michel Dennefeld (dennefel@iap.fr)
Subjects: Optical, Nova, Variables
We report the classification of the transient Gaia16afz, detected on Feb. 2016-02-24, 17:18 UT
at mag.15.3 by the ESA GAIA mission (supplied by DPAC and the Photometric Science Alerts Team, http://qsaweb.ast.cam.ac.uk/alerts ). Three consecutive observations of 300 sec each were performed with the ESO New Technology Telescope at LaSilla, starting on 2016 Feb. 29 at 08:27 UT, using EFOSC2 and Grism 13 (3985-9315, 18 A resolution) and then combined to increase the S/N.
The spectrum shows a blue continuum with prominent Balmer emission lines of Halpha, Hbeta, Hgamma,
and Hdelta, the latter three superimposed on a broader absorption. Strong HeI emission lines are seen at 5016 and 5876 A, while weaker HeI emission lines are also detected at 4026, 4921 and 7071A. No HeII line is seen on this spectrum.
This object suffered a 5 mag rise with respect to a previous detection as LSQ 14vr (LaSilla Quest, Baltay et al. 2013, PASP, 125, 683) in Feb. 2014. The previous spectrum, obtained by PESSTO on Feb. 2014-02-23 (ATel 5914) showed only Balmer absorption lines superposed on a blue continuum.
Gaia16afz is thus classified as a dwarf nova in eruption.
