Hubble spots farthest supernova yet

NASA's Hubble Space Telescope has detected the farthest Type Ia supernova ever seen which is believed to have exploded more than 10 billion years ago.
Supernova UDS10Wil, nicknamed SN Wilson after former US President Woodrow Wilson, belongs to a special class called Type Ia supernovae.
These bright beacons provide a consistent level of brightness that can be used to measure the expansion of space. They also yield clues to the nature of dark energy, the mysterious force accelerating the rate of expansion.
"This new distance record holder opens a window into the early universe, offering important new insights into how these stars explode," said David O Jones of Johns Hopkins University in Baltimore, lead author of the study.

"We can test theories about how reliable these detonations are for understanding the evolution of the universe and its expansion," Jones said in a statement.
The discovery was part of a three-year Hubble programme, begun in 2010, to survey faraway Type Ia supernovae and determine whether they have changed during the 13.8 billion years since the explosive birth of the universe.

Astronomers took advantage of the sharpness and versatility of Hubble's Wide Field Camera 3 to search for supernovae in near-infrared light and verify their distance with spectroscopy.
So far, the team led by Adam Riess of the Space Telescope Science Institute in Baltimore, has uncovered more than 100 supernovae of all types and distances, looking back in time from 2.4 billion years to more than 10 billion years.

Of those new discoveries, the team has identified eight Type Ia supernovae, including SN Wilson, that exploded more than 9 billion years ago.
Although SN Wilson is only 4 per cent more distant than the previous record holder, it pushes roughly 350 million years farther back in time.
A separate team led by David Rubin of the US Energy Department's Lawrence Berkeley National Laboratory in California announced the previous record just three months ago.
The team's preliminary evidence shows a sharp decline in the rate of Type Ia supernova blasts between roughly 7.5 billion years ago and more than 10 billion years ago.

The steep drop-off favours the merger of two white dwarfs because it predicts that most stars in the early universe are too young to become Type Ia supernovae.
The team's results will be published in The Astrophysical Journal.