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Abell-35 phenomena in symbiotic stars: discovery of 1.2 and 6.4 day periods in vv8 (v471 per)

We are collected high precision (median value of total error bud- get 0.008, 0.006, 0.006, 0.004 mag for B, V , RC, IC bands, respectively) opti- cal photometry of VV8, so far 782 individual observing runs uniformly dis- tributed over the period 2005-2011. This data set allows us to refine the known long periodicity of VV8 to P=16.8 yr, with peak-to-valley amplitudes of
B=0.18 and
V=0.14 mag. In addition, we have discovered two new period- icities: 6.431 day (total amplitude
B=
V=
I=0.05 mag) and 1.184882 day (
B=0.022,
V=0.018,
I=0.014 mag). These two short periods are reminis- cent of the Abell-35 phenomena displayed by binary nuclei of planetary nebulae that have gone through a common envelope phase. Twice the 6.431 day period would nicely correspond to the double-peaked light-curve that the G5III star in VV8 would display if ellipsoidally distorted by filling its Roche lobe.

planetary nebulae: central star – stars: symbiotic binaries – common envelope

Rad je prezentiran na skupu ASIAGO Meeting on symbiotiy stars, održanom od 10.-11.2011., Padova, Italija.