An energetic explosion in the cosmos has been discovered via its not-so-energetic afterglow
K, said that just four minutes after it received Swift's trigger, the telescope found the burst's visible afterglow
and began making thousands of measurements.
Several teams used giant optical telescopes to catch the burst's fading infrared afterglow
This allows Swift to catch afterglows
in their brightest early phases, seconds to minutes after the explosion.
Although gamma-ray bursts are absorbed by Earth's atmosphere, their afterglows
shine at wavelengths, ranging from visible light to radio, that can be recorded at ground level.
Gamma-ray bursts - the universe's most luminous explosions - create bright afterglows
Their bright afterglows
continue for days, sometimes weeks, allowing groundbased telescopes to localize and identify their sources: massive, black-hole-spawning supernovae.
The Swift spacecraft, launched by NASA late last November to study gamma-ray bursts and their afterglows
, recorded the X rays on Jan.
Both Swift and HETE-2 can pinpoint the location of bursts quickly, allowing a variety of telescopes to study the fading afterglows
They have shown a striking absence of afterglows
--and it is only by afterglows
that bursts can be accurately located.
The findings support the notion that these brilliant bursts and their afterglows
can enable astronomers to study galaxies that lie too far away and are too dusty for the scientists to easily observe.
Previous missions, such as Italy's BeppoSAX and the international High Energy Transient Explorer 2, made steps toward pinpointing them, but Swift takes a different approach--it's optimized to detect GRB afterglows
with a trio of specialized instruments.
But these afterglows
have been too small for a telescope to discern their spatial structure.
The X-ray and radio afterglows
of the titanic burst were also extremely bright.
Lasting from hours to days, these afterglows
reveal that the bursts come from distant galaxies, many of them with the bluish tinge and dusty appearance typical of regions that churn out young stars, including massive ones, at an enormous rate.