Farther than the farthest star?...........maybe not:
http://science.nasa.gov/science-news/science-at-nasa/2009/28apr_grbsmash/
Close, but no cigar, exploding or otherwise. The galaxy is MORE THAN 13 billion light years away. The long-dead star that created the gamma-ray burst, a 'mere' 13 billion LY.
From your link...
"April 28, 2009: NASA's Swift satellite and an international team of astronomers have found a gamma-ray burst from a star that died when the universe was only 630 million years old--less than five percent of its present age. The event, dubbed GRB 090423, is the most distant cosmic explosion ever seen.
(snip)
The burst occurred at 3:55 a.m. EDT on April 23rd. Swift quickly pinpointed the explosion, allowing telescopes on Earth to target the burst before its afterglow faded away. Astronomers working in Chile and the Canary Islands independently measured the explosion's redshift. It was 8.2, smashing the previous record of 6.7 set by an explosion in September 2008. A redshift of 8.2 corresponds to a distance of 13.035 billion light years."