THE SEYFERT-GALAXY NGC-6814 - A HIGHLY VARIABLE X-RAY SOURCE

The Seyfert galaxy NGC 6814 is a highly variable X-ray source despite the fact that it has recently been shown not to be the source of perio dic variability. The 1.5 year monitoring by ROSAT has revealed a long term downward trend of the X-ray flux and an episode of high and rapid ly varying flux (e.g. by a factor of about 3 in 8 hours) during the Oc tober 1992 PSPC observation. Temporal analysis of this data using both Fourier and autoregressive techniques have shown that the variability timescales are larger than a few hundred seconds. The behavior at hig her frequencies can be described by white noise.