(PhysOrg.com) -- The stellar explosions known as type 1a
supernovae have long been used as "standard candles," their
uniform brightness giving astronomers a way to measure cosmic
distances and the expansion of the universe. But a new study
published this week in Nature reveals sources of variability in
type 1a supernovae that will have to be taken into account if
astronomers are to use them for more precise measurements in the
future. The discovery of dark energy, a mysterious force that is
accelerating the expansion of the universe, was based on
observations of type 1a supernovae. But in order to probe the
nature of dark energy and determine if it is constant or
variable over time, scientists will have to measure cosmic
distances with much greater precision than they have in the
past. "As we begin the next generation of cosmology experiments,
we will want to use type 1a supernovae as very sensitive
measures of distance," said lead author Daniel Kasen, a Hubble
postdoctoral fellow at the University of Califor