X RAY TELESCOPE(1978)

NASA Launches a super sensitive, orbiting telescope

The earth atmosphere is opaque to x ray spectrum so that x rays telescopes must be mounted on high altitude rockets, artificial satellite or balloons. XRT is designed to observe object in the X rays spectrum

X rays absorbed by the earth’s atmosphere so one has to climb above the atmosphere to see them. NASA’s Uhuru (1970) and the united kingdom’s Ariel V (1974) were spin stabilized satellite that discovered around 400 bright sources .astronomers realized that X ray provide vital clues to the detail throws of stars, specifically supernova explosions and the final transition to white dwarf, neutron star, and black hole states. X rays are a vital component of the radiation coming from energetic such as solar flares.

Ultraviolet telescopes study very hot stars and optical telescope study the visible light from space. because these rays (such as X rays, gamma rays, infrared, most ultraviolet) blocked by the outer atmosphere these type of light can only study from space

Two technical advances helped the development of space telescope. One was the construction of advanced Confocal mirror system and the other was the development of two dimensional X ray images gas scintillation proportional counters. Using these United States launched the first orbiting satellite containing a fully imaging X rays telescope, the high energy astrophysical observatory 2 (HEAO-2), In November 1978.

HEAO-2 was renamed “Einstein” when it was in orbit and operating correctly. Einstein discovered that nearly all astronomical bodies emit       X rays. Also the angular resolution and the sensitivity were such that accurate maps could be made of object such as the Cygnus loop supernova remnant. The Einstein instruments were a thousand times more sensitive than those on Uhuru.

Einstein remained operational until April 1981. Other space telescopes have followed, such as Exosat, Rosat, Chandra, and XXM Newton, and all have continued the quest or ever higher details and sensitive. In addition to new sources being discovered, it has been found that many X rays are being emitted as materials falls into the black holes at the center of active galactic nuclei.