On Dec. 25, 2010, NASA's Swift telescope detected a massive gamma ray burst (GRB) in the constellation Andromeda. The unusually long emission lasted at least 28 minutes. Its length and source left scientists puzzled.
Astronomers quickly developed two very different theories to explain what was quickly dubbed the "Christmas burst." One is that a comet-like body fell into a neutron star in our own galaxy. In the other scenario, a neutron star was engulfed by an evolved giant star in a distant galaxy. Whatever its origin, the result was spectacular.
Of all the phenomena in the Universe, GRBs are among the most mysterious. These powerful bursts are the Universe's most luminous explosions, emitting more energy in a few seconds than our sun will during its entire existence. They appear almost daily without warning, come from any direction in the sky, last from a few milliseconds to nearly a half hour, and have no clear causes.
For decades, scientists have been left to speculate with a shortage of solid data to go on. That situation changed on Nov. 20, 2004, when a Delta rocket launched the Swift telescope into Earth orbit. The American space agency operates this first-of-its-kind multi-wavelength observatory in collaboration with partners in Italy, Germany, Japan, and the United Kingdom.
Swift has three instruments that study GRBs and their afterglow: the Burst Alert Telescope (BAT), the X-ray Telescope (XRT), and the Ultraviolet/Optical Telescope (UVOT). BAT is the largest of the instruments, and it keeps a continuous look at one-sixth of the sky at a time. Once BAT detects a burst, it signals to spacecraft to reposition itself to allow XRT and UVOT to study the emission.
Swift Telescope and Swift XRT Image of Supernova Remnant RCW 103
The satellite relays data on a GRB to the ground, where they are distributed for follow-up study. Observatories around the world are able to observe the burst’s afterglow, providing valuable data that supplement those from the Swift telescope.
The orbiting observatory was named Swift after a bird of the same name that can quickly change its angle of flight, much the way the spacecraft can shift its position to cover a sudden gamma ray burst.
Swift’s instruments are able to measure a GRB's red shift, which enables scientists to calculate the burst’s distance and absolute brightness. The instruments also provide detailed multi-wavelength light curves for the duration of the afterglow, allowing astronomers to examine the physical environment in which the event took place.
Since its launch, Swift has detected hundreds of GRBs, providing scientists with data to refine their theories about these mysterious phenomena. The GRBs could signal the birth of a black hole in a massive stellar explosion. Or they could be the result of a collision between two neutron stars. Or they could signal something else entirely. Scientists don’t know for sure, but thanks to Swift, they are getting closer to finding answers.
Link for Swift Telescope
Swift Telescope Website