Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-09-14
Astronomy and Astrophysics
Astrophysics
13 pages, 5 figures, to appear in PASP, Dec. 1998 issue
Scientific paper
10.1086/316277
We detected a new AM Her star serendipitously in a 25 day observation with the EUVE satellite. A coherent period of 85.82 min is present in the EUVE Deep Survey imager light curve of this source. A spectroscopic identification is made with a 19th magnitude blue star that has H and He emission lines, and broad cyclotron humps typical of a magnetic cataclysmic variable. A lower limit to the polar magnetic field of 46 MG is estimated from the spacing of the cyclotron harmonics. EUVE J0425.6-5714 is also detected in archival ROSAT HRI observations spanning two months, and its stable and highly structured light curve permits us to fit a coherent ephemeris linking the ROSAT and EUVE data over a 1.3 yr gap. The derived period is 85.82107 +/- 0.00020 min, and the ephemeris should be accurate to 0.1 cycles until the year 2005. A narrow but partial X-ray eclipse suggests that this object belongs to the group of Am Her stars whose viewing geometry is such that the accretion stream periodically occults the soft X-ray emitting accretion spot on the surface of the white dwarf. A non-detection of hard X-rays from ASCA observations that are contemporaneous with the ROSAT HRI shows that the soft X-rays must dominate by at least an order of magnitude, which is consistent with a known trend among AM Her stars with large magnetic field. This object should not be confused with the Seyfert galaxy 1H 0419-577 (= LB 1727), another X-ray/EUV source which lies only 4' away, and was the principal target of these monitoring observations.
Eracleous Michael
Halpern Jules P.
Leighly Karen M.
Marshall Herman L.
Storchi-Bergmann Thaisa
No associations
LandOfFree
EUVE J0425.6-5714: A Newly Discovered AM Herculis Star does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with EUVE J0425.6-5714: A Newly Discovered AM Herculis Star, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and EUVE J0425.6-5714: A Newly Discovered AM Herculis Star will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-724610