The Photometric Period and Variability of the Cataclysmic Variable V849 Herculis (PG 1633+115)

We report time-resolved photometry of the cataclysmic variable V849 Her, and measure a period of 0.1414 \pm 0.0030 days (3.394 \pm 0.072 hours). We also present photometry taken over several weeks in 2010 and 2011, as well as light curves from 1995 to 2011 by the American Association of Variable Star Observers. The spectra, absolute magnitude derived from infrared magnitudes, and variability all suggest that V849 Her is a nova-like variable. The shallow (0.5-magnitude) low states we observe resemble the erratic low states of the VY Sculptoris stars, although they may recur quasi-periodically over an average cycle of 12.462 \pm 0.074 days.Comment: 18 pages, 9 figures, accepted for publication in New Astronom

The Orbital Period and Negative Superhumps of the Nova-Like Cataclysmic Variable V378 Pegasi

A radial velocity study is presented of the cataclysmic variable V378 Pegasi (PG 2337+300). It is found to have an orbital period of 0.13858 +/- 0.00004 d (3.32592 +/- 0.00096 hours). Its spectrum and long-term light curve suggest that V378 Peg is a nova-like variable, with no outbursts. We use the approximate distance and position in the Galaxy of V378 Peg to estimate E(B-V) = 0.095, and use near-infrared magnitudes to calculate a distance of 680 +/- 90 pc and M_V = 4.68 +/- 0.70, consistent with V378 Peg being a nova-like. Time-resolved photometry taken between 2001 and 2009 reveals a period of 0.1346 +/- 0.0004 d (3.23 +/- 0.01 hours). We identify this photometric variability to be negative superhumps, from a precessing, tilted accretion disk. Our repeated measurements of the photometric period of V378 Peg are consistent with this period having been stable between 2001 and 2009, with its negative superhumps showing coherence over as many as hundreds or even thousands of cycles.Comment: 24 pages, 19 figures, accepted for publication in New Astronom