What if you had a “Wayback Television Set” and could watch an entire month of ancient prehistory unfold before your eyes in real time? David Rubin of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory presented just such a scenario to the American Astronomical Society (AAS) meeting when he announced the discovery of a striking astronomical object: a Type Ia supernova with a redshift of 1.71 that dates back 10 billion years in time. Labeled SN SCP-0401, the supernova is exceptional for its detailed spectrum and precision color measurement, unprecedented in a supernova so distant.

“This is the most distant supernova anyone has ever found for doing dependable cosmology,” said Rubin. “The most important unanswered question we have about the nature of dark energy is whether it varies over time – whether it affects the expansion of the universe differently in different eras. With SN SCP-0401, we have the first example of a well-measured supernova sufficiently far away to study the expansion history of the universe from almost 10 billion years ago.”