A Cosmic Explosion with the Force of a Billion Suns Went Unseen—Until We Caught Its Echo

Image Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab

Some of the universe’s most extreme explosions leave behind almost no trace. The original explosion is unseen, but our observations can capture the long-lived echo it leaves behind as the shock front plows into its surrounding environment. In new research accepted for publication in The Astrophysical Journal, we have discovered what may be the clearest example yet of one of these hidden explosions: the radio afterglow of a powerful gamma-ray burst whose initial blast went unnoticed.

The only other viable explanation for what we see is an extraordinarily rare event in which a star is torn apart by an intermediate-mass black hole: a long-hypothesized, elusive class of black holes that has proven difficult to detect.

Either way, we’re watching the slow-motion aftermath of one of the most extreme, rare events the cosmos can produce.

(Source: phys.org)