Selected EUVE Timing Results on AM Herculis Binaries

We present Extreme Ultraviolet Explorer (EUVE) timing results for AM Her, VV Pup, and EUVE J2115-586. We obtained an EUVE target of opportunity observation of AM Her in a high accretion state between 04 August 09:42 -05 August 12:28 1998 UT. The Deep Survey (DS) Lexan filter ( ~ 100 Angstroms) count rate was 2.57+/-0.05 cts/sec. This observation was made simultaneously with Rossi-XTE with the goal of testing correlations in the EUV and X-ray bands. We will present EUVE and RXTE PCA phased light curves and timing studies. We have searched archival EUVE data of VV Pup (February 1993) for the 1-3 sec optical quasi-periodic oscillations (QPO). We found no significant features in the 0.3-1.0 Hz range for the total light curve and light curves separated as a function of orbital phase. We also searched archival EUVE data of AM Her (September 1993 and March 1995) for the ~ 6 minute QPO reported by Stella et al. 1986 using Einstein observations. All features found in the ~ 6 minute range are higher harmonics of the beating between the AM Her and EUVE orbital periods. We also present our October 1997 EUVE observation of asynchronous polar EUVE J2115-586. The source was in a low state with a DS Lexan count rate of 7+/-3 cts/ksec. The EUVE light curve favors a period of 110.4 minutes, similar to the one derived from optical observations by Vennes et al. 1997, but further observations are needed. This research is supported by NASA Grant NAG5-7013.