HST Observations of GRO J1655-40 in Outburst

We examine the results of a coordinated HST-RXTE-CGRO campaign to study the microquasar GRO J1655-40 during its 1996-7 outburst, focusing on interpretation of the overall anti-correlation seen between optical and X-ray fluxes during the early months of the outburst. Our tools include echo-mapping, optical/UV continuum spectral modelling and analysis of spectral variability. We conclude by suggesting one possible interpretation for the anti-correlation.Comment: 4 pages with 11 postscript figures included. To appear in New Astronomy Reviews, as part of proceedings of 2nd Workshop on Galactic Sources with Relativistic Jets. Uses newarcrc.sty (included

Factors affecting handling qualities of a lift-fan aircraft during steep terminal area approaches

The XV-5B lift-fan aircraft was used to explore the factors affecting handling qualities in the terminal area. A 10 deg ILS approach task was selected to explore these problems. Interception of the glide slope at 457.2 m, glide slope tracking, deceleration along the glide slope to a spot hover were considered. Variations in airplane deck angle, deceleration schedule, and powered-lift management were studied. The overall descent performance envelope was identified on the basis of fan stall, maximum comfortable descent rate, and controllability restrictions. The collective-lift stick provided precise glide slope tracking capability. The pilot preferred a deck-parallel attitude for which he used powered lift to control glide slope and pitch attitude to keep the angle of attack near zero. Workload was reduced when the deceleration schedule was delayed until the aircraft was well established on the glide slope, since thrust vector changes induced flight path disturbances

The X-ray Transient XTE J2012+381

We present optical and infrared observations of the soft X-ray transient (SXT) XTE J2012+381 and identify the optical counterpart with a faint red star heavily blended with a brighter foreground star. The fainter star is coincident with the radio counterpart and appears to show weak H alpha emission and to have faded between observations. The RXTE/ASM lightcurve of XTE J2012+381 is unusual for an SXT in that after an extended linear decay, it settled into a plateau state for about 40 days before undergoing a weak mini-outburst. We discuss the nature of the object and suggest similarities to long orbital period SXTs.Comment: 5 pages, 7 postscript figures included, uses mn.sty. Accepted for publication in MNRA