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Paper: |
Magnetically disrupted discs in long-supercycle SU UMa stars? |
Volume: |
157, Annapolis Workshop on Magnetic Cataclysmic Variables |
Page: |
401 |
Authors: |
Mennickent, R. E.; Arenas, J. |
Abstract: |
We have estimated line emissivity (propto r^{-alpha}) and disc radius (R equiv rin/rout) for 8 SU UMa stars. Most stars fit alpha = 1.8 plus or minus 0.1 but AK Cnc and WZ Sge strongly deviate from the mean; their emission lines shapes can be explained assuming a post-outburst accretion disc mostly emitting close to the white dwarf (AK Cnc) and a ring-like disc (WZ Sge). In addition, we have found a tendency for long-supercycle SU UMa stars to show very compact (large R; probably ring-like) accretion discs. If the supercycle length were basically controlled by the mass transfer rate (dot{M}), the inner disc radius would be a function of dot{M}. A white dwarf magnetic field 5000 G is required to fit the truncation radius with the magnetospheric radius of SU UMa stars. |
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