Five Dwarf Novae with Orbital Periods below Two Hours

We give mean spectra and report orbital periods Porb based on radialvelocities taken near minimum light for five dwarf novae, all of which prove tohave Porb less than 2 hr. The stars and their periods are KX Aql, 0.06035(3) d;FT Cam, 0.07492(8) d; PU CMa, 0.05669(4) d; V660 Her, 0.07826(8) d;, and DMLyr, 0.06546(6). The emission lines in KX Aql are notably strong and broad, andthe other stars' spectra appear generally typical for short-period dwarf novae.We observed FT Cam, PU CMa, and DM Lyr on more than one observing run andconstrain their periods accordingly. Differential time-series photometry of FTCam shows strong flickering but rules out deep eclipses. Although dwarf novaein this period range generally show the superhumps and superoutburstscharacteristic of the SU UMa subclass of dwarf novae, none of these objectshave well-observed superhumps.Comment: 14 pages, three figures. Accepted for PAS