A 6.3-h superhump in the cataclysmic variable TV Columbae: the longest   yet seen
  We present results from a two week multi-longitude photometric campaign on TV Col held in 2001 January. The data confirm the presence of a permanent positive superhump found in re-examination of extensive archive photometric data of TV Col. The 6.3-h period is 15 per cent longer than the orbital period and obeys the well known relation between superhump period excess and binary period. At 5.5-h, TV Col has an orbital period longer than any known superhumping cataclysmic variable and, therefore, a mass ratio which might be outside the range at which superhumps can occur according to the current theory. We suggest several solutions for this problem. 
A. Retter (University of Sydney and Keele University), C. Hellier   (Keele University), T. Augusteijn (Nordic Optical Telesc...