I present the first X-ray observations of the red giant, 4 Draconis—thought to have an AM Her companion. I find evidence for absorption by the ionised wind of the red giant, but no sign of the soft X-ray emission typical of (high-state) AM Hers.

The difficulties associated with numerical simulation of accretion discs are outlined along with a potential treatment, FLAME. This technique bridges the gap between existing finite difference codes and particle methods in modern computational fluid dynamics (CFD).

The flickering phenomenon in cataclysmic variables (CVs) is manifest photometrically as variations in system brightness with amplitudes up to about 1 mag and on timescales from seconds to tens of minutes. Although a pronounced characteristic of CVs, flickering has been studied, in general, only tangentially and in the context of overall CV photometric properties. It is usually uncovered in CV photometry, yet my Doppler tomographic analysis of data collected on the KPNO 2.1-meter telescope in 1982 by Schlegel, Honeycutt, and Kaitchuck (1983) for the nova-like variable UX Ursa Majoris suggests that flickering also exists in this system’s spectroscopy.

Using the integrated continuum flux from the UX UMa observations and Bruch’s (1992) methodology for classifying high- and low-flicker data, I constructed two data subsets corresponding to high- and low-flicker states. I generated Doppler tomograms of these high- and low-flicker states and interpret differences between the tomograms as spectroscopic signatures of flickering in the system.

In UX UMa’s Hβ Doppler tomograms, a small, faint, incomplete ring of emission is visible for both flickering states. Dominating ring emission is strong emission in the (+Vx,+Vy) quadrant. The usual location for Swave emission, in the (−Vx,+Vy) quadrant, is here the region of faintest emission. Differenced Doppler tomograms, produced by subtracting from the tomograms the symmetric ring-emission component, show clear differences between the high- and low-flicker states. Further, these early results suggest Doppler tomography may be a useful technique for studying the secondary stars in CVs imaged in this manner. Enhanced chromospheric activity of the red dwarf companion is clearly visible in the high-flickering state tomogram at (0, Krd) and may, therefore, afford investigators the opportunity to estimate the chromospheric flux and radial velocity of the secondary star.

We discuss some of the issues raised by the X-ray, radio and optical observations made during the 1994 outbursts of GRO J1655–40.

We have obtained new optical spectropolarimetric data for the radio-quiet Seyfert NGC 1068, taken through apertures on the nucleus and at two positions within the ionization/scattering cone. The equivalent width of scattered broad-Hβ at these positions, is consistent with the presence of intrinsically beamed continuum radiation.

We present photometric and spectroscopic evidence of two new T Tauri stars formed in the conditions of isolated small Bok globules. The spectral energy distributions of these objects display excess infrared emission, they are associated with optical reflection nebulae, and their optical spectra reveal Balmer emission lines and the Li I λ6707 Å absorption line. Additionnally, we report the discovery of what is likely to be a new FU Orionis star seen towards Bok globule CB34. The star is about 4 magnitudes brighter than it appears on the Palomar plates and is associated with the aggregate of young stellar objects forming in Bok globule CB34.

A new physical mechanism responsible for producing significant radial mass accretion in the inner disk of spiral galaxies has recently been found (Zhang 1996, ApJ, 457, 125). Since this mechanism depends only on the skewness of the global patterns (one-armed or two-armed spiral patterns, as well as skewed central bars) in the underlying disks, and since this process is collective in nature and produces an effective viscosity many orders of magnitude larger than that due to the microscopic processes, it is likely to be an important candidate for the long soughtafter “anomalous viscosity” in many types of astrophysical accretion disks which admit nonaxisymmetric instabilities.

It is assumed that the acceleration and collimation mechanisms of jets are the same in all the classes of astrophysical objects which are observed to produce jets. These classes now include: active galactic nuclei, young stellar objects, massive x-ray binaries, low mass x-ray binaries, black hole x-ray transients, symbiotic systems, planetary nebulae, and supersoft x-ray sources.

On the basis of this assumption, an attempt is made, to identify the necessary ingredients for the acceleration and collimation mechanism. It is argued that: (i) jets are produced at the center of accretion disks which are threaded by a vertical magnetic field, (ii) the production of powerful jets requires, in addition, an energy/wind source associated with the central object. Tentative explanations for the presence of jets in some classes of objects and absence in others are given. Some critical observation that can test the ideas presented in this paper are suggested.