Ultraviolet spectroscopy of symbiotic nova V1016 Cyg with IUE and HST

Abstract

We present International Ultraviolet Explorer (IUE) & Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) observations of the symbiotic nova V1016 Cyg through the period 1978 – 2000. Four spectra at different times revealing the changes in line fluxes are presented. The outflow velocity of the emitting region was calculated to be 900–2000km s−1 (FWHM). The reddening of V1016 Cyg was determined from 2200Å absorption feature to be E (B-V) = 0.36±0.02.We calculated the fluxes of CIV 1550Å & CIII] 1909Å emission lines produced in a stellar wind from the hot white dwarf. We determined the average wind mass loss rate to be ∼2.3×10–6 M⊙, the average temperature of the emitting region to be ∼1.3×105K, and an average ultraviolet luminosity to be ∼2×1035erg s−1.The results show that there are modulations of line fluxes with time. We attributed these spectral modulations to the changes of density and temperature in the emitting region as a result of the variable stellar wind.