Multiwavelength evidence for a 15-year periodic activity in the symbiotic nova V1016 Cygni

Abstract

The ~ 15.1 years period found in the long-term UBV photoelectric and photographic photometry of the symbiotic nova V1016 Cyg is detected also in the (J-K) colour index and in the UV continuum and emission line fluxes from IUE and HUT spectra. It could be interpreted either as the effect of recurrent enhanced mass loss episodes from the Mira type variable companion to a hot component along its ultra-wide orbit (proposed from recent HST observations) or the true orbital period of the inner, unresolved binary of a triple system. The 410-day delay of the maximum of UV emission lines fluxes with respect to the maximum of continuum was found. The pulsation period of the Mira type variable was improved to 474+/-6 days. Partly based on observations obtained with the International Ultraviolet Explorer (IUE) satellite retrieved from the IUE Newly Extracted Spectra (INES) Archive and the Hopkins Ultraviolet Telescope (HUT) retrieved from the Multimission Archive at STScI (MAST).