MOSCOW, OCT. 3 -- Soviet and Japanese scientists today confirmed the first sightings of X-rays from an exploding star viewed from the Southern Hemisphere, providing the first intriguing glimpses ever achieved into the heart of a stellar death.

Rashid Sunyaev, director of astrophysics for the Soviet Space Research Institute, reported today that the first positive detection occurred Aug. 10, using X-ray telescopes aboard the Soviet astrophysics module Kvant, which is docked to the space station Mir.

Japanese scientists first observed the supernova X-rays Aug. 15 using smaller X-ray instruments aboard their Ginga satellite, according to Minoru Oda, head of Japan's Institute of Space and Astronautical Science.

The supernova, 170,000 light years from Earth, burns with the brilliance of 100 million suns and gives off much of its energy in the form of X-rays from its core. The X-rays do not penetrate the Earth's atmosphere and can only be observed from space.

This is the first time X-ray telescopes have been in place to observe the unimaginable forces inside a supernova that are believed to be the crucible for the creation of worlds and of life itself.

Scientists had anticipated the arrival of the X-rays anywhere from two months to a year and a half after the supernova was sighted in February. The expanding outer gaseous shell of a supernova is so thick at first that X-rays cannot escape.

The scientists reported their findings during a special session of the Space Future Forum here held to mark the 30th anniversary of the first space satellite, the Sputnik.

Frustrated American astronomers said the United States has no X-ray telescope in space currently.

The most striking characteristic revealed by the new observations is that the shell of the supernova is extremely "hard" -- that the energy has a high ratio of hard X-rays to soft X-rays. "It is harder than any object we've observed up to now," Sunyaev said.