(the following information provided by Dr. Pierre Chayer)
Drs. Jules Halpern (Columbia Astrophysics Laboratory) and Herman Marshall (Center for Space Research, MIT) performed a long observation of the Seyfert Galaxy RX J0437.4-4711 with the Extreme Ultraviolet Explorer satellite (EUVE). They monitored the soft X-ray Seyfert galaxy for 20 days. The Seyfert Galaxy was detected in the 70-110 Angstrom range, both in the short-wavelength spectrometer and in the Deep Survey imager.
Its light curve shows large-amplitude variability by a factor of 4 over the 20 day period, and a minimum doubling time of 5 hours. A possible period of 0.9 days is the main feature of the light curve and power spectrum. Such long, continuous satellite observations of AGNs are rare, and this observation is one of the few that are sensitive to transient periods of order one day, a time scale that might correspond to orbital motion in the inner accretion disk around a 10**8 M_sun black hole.
This Seyfert galaxy was a secondary target in the field. The primary target of the observation was the 5.75 millisecond pulsar PSR J0437-4715, for which we used the high time resolution mode of EUVE to measure its pulsed light curve with high signal-to-noise ratio.
Drs. Frits Paerels (Space Science Laboratory, University of California at Berkeley), Min Young Hur (Department of Physics, University of California at Berkeley) Christopher Mauche (Lawrence Livermore Laboratory) and John Heise (SRON Laboratory for Space Research, Utrecht, Netherlands) obtained and analyzed the EUVE spectrum of the white dwarf in AM Herculis in the 75-120 Angstrom band. They detected ionization edges and absorption lines from highly ionized neon (Ne VI, Ne VIII), but they did not detect absorption at the O VI 2s, 2p edges, which are expected to be the strongest spectral features in this band in an atmosphere of solar composition at the density and temperature expected for the accretion region in this object.
Drs. J. Schmitt (Max-Planck-Institut fur Extraterrestrische Physik, Federal Republic of Germany) R. Stern (Solar and Astrophysics Laboratory, Lockheed Palo Alto Research Laboratory), J. Drake (SAO), and M. Kurster (Max-Planck-Institut fur Extraterrestrische Physik, Federal Republic of Germany) obtained with the short-wavelength (SW) spectrometer on board the Extreme Ultraviolet Explorer (EUVE) satellite, a spectrum of the RS CVn binary CF Tuc. The RS CVn CF Tuc consists of a G0V dwarf star and an K4IV evolved star in a synchronous orbit of 2.9 days. They detected only two spectral lines attributed to Fe XXII and Fe XXIII in addition to the continuum. Using the EUVE data and ROSAT PSPC spectra, Dr. Schmitt's group demonstrated that the iron abundance in the corona of CF Tuc is reduced with respect to solar values by factors between 5 and 10. They proposed to designate this phenomenon as the ``metal abundance deficiency syndrome'' (MADS).