GRB’s Could Indicate The Collapse Of A Star And The Birth of A Black Hole
The Swift Spacecraft was launched in Nov 2004 and has been detecting GRB’s on a regular basis ever since. As Swift continues to detect Scientists collect all the data to understand more the massive physical process that’s taking place. These are by far the most powerful explosions that take place in the Universe and point to the death of a massive star and the birth of a massive black hole.
Check out the short video below for some fantastic animation of a Gamma Ray Burst
A GRB is a fleeting blast of high-energy light, often lasting a minute or less, occurring somewhere in the sky every couple of days. Scientists are looking for exceptional bursts that offer the deepest insights into the extreme physical processes at work.
Shortly before 6:41 p.m. EDT on Oct. 27, Swift’s Burst Alert Telescope detected the 1,000th GRB as a sudden pulse of gamma rays arising from a location toward the constellation Eridanus. Astronomers dubbed the event GRB 151027B, after the detection date and the fact that it was the second burst of the day. Swift automatically determined its location, broadcast the position to astronomers around the world, and turned to investigate the source with its own sensitive X-ray, ultraviolet and optical telescopes.
IMAGE: THIS ILLUSTRATION SHOWS THE POSITIONS OF 1,000 SWIFT GRBS ON AN ALL-SKY MAP ORIENTED SO THAT THE PLANE OF OUR GALAXY, THE MILKY WAY, RUNS ACROSS THE CENTER. CREDITS: NASA’S GODDARD SPACE FLIGHT CENTER AND 2MASS/J. CARPENTER, T. H. JARRETT, AND R. HURT
Astronomers classify GRBs by their duration. Like GRB 151027B, roughly 90 percent of bursts are of the “long” variety, where the gamma-ray pulse lasts more than two seconds. They are believed to occur in a massive star whose core has run out of fuel and collapsed into a black hole. As matter falls toward the newly formed black hole, it launches jets of subatomic particles that move out through the star’s outer layers at nearly the speed of light. When the particle jets reach the stellar surface, they emit gamma rays, the most energetic form of light. In many cases, the star is later seen to explode as a supernova.
“Short” bursts last less than two seconds — and sometimes just thousandths of a second. Swift observations provide strong evidence these events are caused by mergers of orbiting neutron stars or black holes.
Once a GRB is identified, the race is on to observe its fading light with as many instruments as possible. Based on alerts from Swift, robotic observatories and human-operated telescopes turn to the blast site to measure its rapidly fading afterglow, which emits X-rays, ultraviolet, visible and infrared light, and radio waves. While optical afterglows are generally faint, they can briefly become bright enough to be seen with the unaided eye.
“Over the years, astronomers have constantly refined their techniques to get their telescopes onto the burst site in the shortest possible time,” said John Nousek, Swift’s director of mission operations and a professor of astronomy and astrophysics at Penn State University in University Park, Pennsylvania. “In fact, the process to follow up Swift GRB alerts is as productive as ever.”