Description
BF Cygni (hereafter BF Cyg) is a symbiotic star that in 2006 July started into an optical outburst that has lasted for several years. Between 2006 August and 2007 January we obtained high-dispersion spectra (r~35,000) over the wavelength range of 3800-10000{AA} of BF Cyg with the 3.5m echelle spectrograph at Apache Point Observatory. The emission lines in the optical spectrum of BF Cyg changed dramatically during the interval of observations. The species found were mostly low-ionization emission lines of H, He, C, N, O, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, and Ni. Both permitted and forbidden lines were seen. In particular, Fe I was observed in emission, which is not a common phenomenon.
|