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- ItemBF Cyg during ITS current outburst(Vilnius : Lithuanian Astronomical Union, 2012) Siviero, A.; Tamajo, E.; Lutz, J.; Wallerstein, G.We are intensively monitoring the current outburst on BF Cyg, both spectroscopically (high and low resolution modes) and photometrically (so far 450 BVRCRIC measurements have been collected). The outburst is photometrically reminiscent of the major event BF Cyg experienced in 1890 when it rose by 4 mag in the blue. In this contribution we present the data and describe the plans to investigate this object.
- ItemAbell-35 phenomena in symbiotic stars: Discovery of 1.2 and 6.4 day periods in VV8 (V471 per)(Vilnius : Lithuanian Astronomical Union, 2012) Munari, U.; Siviero, A.; Tamajo, E.; Fiaschi, M.; Dallaporta, S.; Cherini, G.; Frigo, A.; Castellani, F.; Graziani, M.; Moretti, S.; Tomaselli, S.We have collected high precision optical photometry of VV8, so far 782 individual observing runs uniformly distributed over the period 2005-2011. This dataset allows us to refine the known long periodicity of VV8 to P = 16.8 yr, with peak-to-valley amplitudes of ΔB = 0.18 and ΔV = 0.14 mag. In addition, we have discovered two new periodicities: 6.431 d (total amplitude Δ = ΔV = ΔI= 0.05 mag) and 1.185 d (ΔB = 0.022, ΔV = 0.018, ΔI = 0.014 mag). These two short periods are reminiscent of the Abell35 phenomena displayed by binary nuclei of planetary nebulae that have gone through a common envelope phase. Twice the 6.431 d period would nicely correspond to the double-peaked light-curve that the G5 III star in VV8 would display if its Roche lobe would be ellipsoidally distorted.