PROPERTIES OF THE EXCEPTIONALLY LONG-PERIOD AM HERCULIS SYSTEM RX J0515.41+0104.6

We show that the properties of the recently discovered AM Her type cat aclysmic variable RX J0515.41+0104.6 can be understood in terms of the standard evolutionary model, which accounts for both the near-synchro nism at the observed period and the size of the mass-donor star. We fi nd that either the system is in a low state long enough to bring the w hite dwarf to synchronism or that the magnetic field of the secondary is strong enough, but not unusually so (greater than or similar to 1 k G), to maintain synchronism at this period and the system may exhibit radio flares.