Further observations of EX Hydrae.

The 98 min orbital period of EX Hydrae was first documented as a result of the spectroscopic data of Kraft and Krzeminski (1962) and the photometric study of Mumford (1964, 1967). Watson et al. (1978) have found that EX Hya emits strongly both hard and soft X-rays in its quiescent state. Such a phenomenon is unique among the dwarf novae. Vogt et al. (1980) demonstrated that there existed a strong 67 min modulation in the light from EX Hya. In order to account for this modulation, three models were suggested. In the present investigation, additional eclipse and 67 min modulation timing measurements are reported, taking into account observations made with a 1 m reflector during 1983. Attention is given to the eclipse ephermeris, the 67 min ephemeris, and a summary of the constraints on the source of the 67 min flux modulation in EX Hya.