Polarimetry and photometry of the new AM Herculis system RE J1844-741

The new long-period AM Herculis system RX J0203.8+2959

We present the first detailed multi-wavelength study of the ROSAT-discovered AM Herculis binary RX J0203.8+2959 comprising extended CCD and photoelectric photometry, phase-resolved spectroscopy with high and low spectral resolution and pointed ROSAT observations with the PSPC and the HRI. Between 1992 and 1997 the system displayed states of high and low accretion with mean brightness levels of ...

High and low states of the system AM Herculis

Context. We investigate the distribution of optically high and low states of the system AM Herculis (AM Her). Aims. We determine the state duty cycles, and their relationships with the mass transfer process and binary orbital evolution of the system. Methods. We make use of the photographic plate archive of the Harvard College Observatory between 1890 and 1953 and visual observations collected ...

Photometry and Polarimetry of Mercury

Am Herculis Binaries in the Rosat Era

The current census of AM Herculis binaries and AM Her candidates exceeds 50 systems of which 29 are ROSAT discoveries. The increased number provides a basis to study the more general properties of the class. We discuss the space density, observations relevant to the evolution of magnetic CVs, the statistics of magnetic eld measurements, and current ideas on the accretion scenarios.

HST / GHRS observations of AM Herculis ⋆

We present phase-resolved spectroscopy of AM Herculis obtained with the HST/GHRS when the system was in a high state. The ultraviolet light curve shows a quasi-sinusoidal modulation, which can be explained by a hot spot on the rotating white dwarf. The broad Lyα absorption expected for photospheric radiation of a moderately hot white dwarf is largely filled in with emission. The UV/FUV spectrum...