Launched Saturday on a Delta rocket , the X-ray Timing Explorer (XTE) will watch the sky for rapid changes in X-rays . XTE carries three separate X-ray telescopes. The Proportional Counter Array (PCA) and the High Energy X-ray Timing Experiment (HEXTE) will provide the best timing information in the widest X-ray energy range yet available. They will observe stellar systems that contain black holes , neutron stars , and white dwarfs as well as study the X-ray properties of the centers of active galaxies . XTE 's All Sky Monitor (ASM) will scan the sky every 90 minutes to find new X-ray transients and track the variability of old ones. XTE has a planned life time of two years.
3 January 1996
The X-ray Timing Explorer
