How much light does a supernova shed on the history of universe?
New research by cosmologists at the University of Chicago and Wayne State University confirms the accuracy of Type Ia supernovae in measuring
the pace at which the universe expands. The findings support a widely held theory that the expansion of the universe is accelerating and such
acceleration is attributable to a mysterious force known as dark energy. The findings counter recent headlines that Type Ia supernova cannot
be relied upon to measure the expansion of the universe.
Using light from an exploding star as bright as entire galaxies to determine cosmic distances led to the 2011 Nobel Prize in physics. The method
relies on the assumption that, like lightbulbs of a known wattage, all Type Ia supernovae are thought to have nearly the same maximum brightness
when they explode. Such consistency allows them to be used as beacons to measure the heavens. The weaker the light, the farther away the star. But
the method has been challenged in recent years because of findings the light given off by Type Ia supernovae appears more inconsistent than expected.
“The data that we examined are indeed holding up against these claims of the demise of Type Ia supernovae as a tool for measuring the universe,”
said Daniel Scolnic, a postdoctoral scholar at UChicago’s Kavli Institute for Cosmological Physics and co-author of the new research published in
Monthly Notices of the Royal Astronomical Society. “We should not be persuaded by these other claims just because they got a lot of attention,
though it is important to continue to question and strengthen our fundamental assumptions.”
Research reinforces role of supernovae in clocking the universe | UChicago News
https://news.uchicago.edu/article/2017/01/03/research-reinforces-role-supernovae-clocking-universe