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K. Mukai (NASA/GSFC and USRA), C. Hellier (U.Keele), G. Madejski (SLAC)
V1432~Aquilae (=RX~J1940.2-1025) is the X-ray bright magnetic cataclysmic variable (mCV) whose X-ray modulations at ~12000 s were once thought to belong to the Seyfert galaxy, NGC~6814, ~37' away. These modulations in fact belong to the mCV, and consists of a 12150 s component caused by the spin of the white dwarf, and a 12116.3 s component defined by a narrow eclipse in the optical and the X-rays. However, the cause of this feature, whether it is a true eclipse by the secondary or a dip caused by the accretion stream, has been the subject of debate. We will report the results of an RXTE monitoring campaign performed in 1998 May through August, during which we observed the eclipse 25 times. The eclipse events are deep, consistent with a total lack of X-rays from V1432~Aql for about 600 s; however, the eclipse profile is variable from epoch to epoch. We will discuss the implications of these findings for the model of this mCV. We will also briefly discuss the X-ray variability of NGC~6814.