Spectroscopy of Seven Cataclysmic Variables with Periods above 5 Hours

We present spectroscopy of seven cataclysmic variable stars with orbitalperiods P(orb) greater than 5 hours, all but one of which are known to be dwarfnovae. Using radial velocity measurements we improve on previous orbital perioddeterminations, or derive periods for the first time. The stars and theirperiods are TT Crt, 0.2683522(5) d; EZ Del, 0.2234(5) d; LL Lyr, 0.249069(4) d; UY Pup, 0.479269(7) d; RY Ser, 0.3009(4) d; CH UMa, 0.3431843(6) d; and SDSS J081321+452809, 0.2890(4) d. For each of the systems we detect the spectrum of the secondary star,estimate its spectral type, and derive a distance based on the surfacebrightness and Roche lobe constraints. In five systems we also measure theradial velocity curve of the secondary star, estimate orbital inclinations, andwhere possible estimate distances based on the MV(max) vs.P(orb) relation foundby Warner. In concordance with previous studies, we find that all the secondarystars have, to varying degrees, cooler spectral types than would be expected ifthey were on the main sequence at the measured orbital period.Comment: 25 pages, 2 figures, accepted for Publications of the Astronomical Society of the Pacifi