Still another big scientific question now being tackled on a national and
international scale is "deceleration"-the rate at which the expansion of the
universe is slowing down. The answer lies in the stars, namely Type Ia
supernovas, the nuclear conflagrations that result from the implosion of a white
dwarf. Type Ia supernovas serve cosmologists as a measurement of distance and a
means of calculating the velocity at which galaxies are receding from Earth. It
is thought that analyzing the spectrums of about 50 type Ia supernovas will be
enough to determine the universe's rate of deceleration.
In December of this past year, a collaboration known as the Supernova
Cosmology Project (SCP), led by Berkeley Lab scientists, announced the discovery
of 11 new Type Ia supernovas, including several of the most distant stars ever
observed. These supernovas were discovered within a 48-hour period, an
unprecedented achievement that validated a Berkeley Lab technique developed to
make deep space supernova discoveries possible and eventually even routine. The
discoveries in 1995, combined with discoveries in 1993 and 1994, bring the total
of Type Ia supernovas identified by the SCP collaboration to 18.