XMM-Newton Observation of the Polar
J. P. Halpern
EUVE J0425.6-5714 is a little-studied AM Her star (Halpern et al. 1998) that was discovered serendipitously in ROSAT and EUVE observations of the bright AGN 1H 0419-577 between 1994 and 1998. It has a period of 85.82 minutes (0.059598 days). Three eclipse timings from another serendipitous observation illustrated below, with XMM-Newton on 2003 September 16, are consistent with the published ROSAT and EUVE ephemeris. Here is an updated and refined ephemeris:
|Teclipse = HJD 2,452,898.7967(6) + 0.05959800(3) × E|
Several additional, shorter XMM-Newton observations are available, with the X-ray source at various levels of intensity. The one illustrated here is the only one that is suitable for eclipse timing.
EUVE J0425.6-5714: A Newly Discovered AM Herculis Star, Halpern, J. P., Leighly, K. M., Marshall, H. L., Eracleous, M., & Storchi-Bergmann, T., P.A.S.P. 110, 1394-1399 (1998).