ultraviolet emissions
Still under development, however changes are made regularly - check back by later.

The Far Ultraviolet Spectroscopic Explorer (FUSE) Spacecraft

FUSE is just ending its shakedown period after a June 1999 launch, at which time FUSE is expected to start studying deuterium, a fossil atom left over from the astronomical Big Bang that astronomers believe gave birth to the universe billions of years ago. This spaceborne observatory is more than 100 times more powerful than any previous far-ultraviolet instruments, and can detect new atomic and molecular constituents of a specific target with greater resolution. By looking at the interstellar medium (ISM), FUSE can determine that targets composition, velocity and distance in relation to objects farther away. For more information on Ultraviolet Spectroscopy, visit "A General Review of Astrophysics."

Thousands of exploding stars have left a telltale halo of searingly hot gas around the Milky Way. Some scientists believed it might have been caused by ultraviolet radiation from hot stars. Other scientists, working with the FUSE spacecraft, have determined that hot stars in the oblate spheroid-shaped halo could not produce the observed atomic residue, which only supernovae can do.

FUSE made the discovery by detecting lots of oxygen VI (OVI) in the halo. "The only way to make the observed amount of oxygen VI is through collision with the blast waves from exploding stars, called supernovae,'' Blair Savage of the University of Wisconsin in Madison, a FUSE scientist, said in a statement.76j

Illustrations

This plot shows the similarity of X-ray and ultraviolet light emissions from the B-emission star gamma Cassiopeiae on March 14--15, 1996. The UV emission from the HST has been inverted and rescaled to emphasize its correspondence with the slow component of the variations of the X-ray emission. 82KB Jpeg Image.

Far-UV spectroscopic observations on underlying white dwarf accreters (explosive central engine) may hold clues to

  1. evolutionary big picture of cataclysmic evolution
  2. evolution across the period gap
  3. whether CV mass decreases over time due to repeated classical nova explosions - or is there a mass increase ?

insight into

  1. long term accretion heating
  2. limit cycle evolution, and
  3. ultimate evolutionary state

These pioneering detections were carried out by Panek & Holm (1984), Shafter, et al. (1985), Mateo and Szkody (1984), Cordova (1995), and Shara (1989). A number of underlying white dwarfs have also been spectroscopically studied by Gansicke and Beuermann (1997) and Sion (1998), which was a deeper study of Teff , log L, and M for CVs vs. Orbital period and CV sub-type

 

 

 

 

 

 

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