Various Gamma-Ray Burst Images
Swift video also available; contact wanjek@gsfc.nasa.gov
A gamma ray burst originating in our neck of the Milky Way, within a thousand light years or so, could lead to mass extinction on earth. Gamma rays interacting in the earth's atmosphere would burn away the ozone layer, allowing deadly ultraviolet radiation to penetrate through the atmosphere. The influx of radiation would lead to widespread cancer and other diseases.
(Credit: P.J.T. Leonard, NASA)
This is an animated movie of what could be neutron star merging with a black hole and producing a gamma-ray burst.
(Credit: STScI)
[download the 2.6 meg MOV file] or [download eight frames as JPEG]
![[download eight frames as JPEG]](GRB_movie.jpg){kind=link}
The optical afterglow of GRB 990123, which as the name indicates appeared on January 23. This exceptionally bright gamma ray burst was the first to be caught with an optical telescope while the burst was actually occurring (see ROTSE image below). This image, from the Hubble Space Telescope, is an afterglow.
(Credit: HST GRB Collaboration/NASA)
Artists conceptions of the Swift satellite observing a supermassive black hole. The black hole's extreme gravitational force accretes gas from the interstellar medium. The gas builds up around the black hole, heats to temperatures of a millions of degrees, and radiates x-rays. Through a little-understood mechanism, jets of x-rays and gamma-rays often shoot for thousands of light-years from opposite ends of the black hole.
These images can also be interpreted as a neutron star / black hole merger, where great amounts of x-ray and gamma-ray energy are released.
(Credit: NASA)
[download #1, 300 dpi TIFF (over 10 megs)] or [download #2, 300 dpi TIFF (6 megs)]
On January 23, 1999, ROTSE (a ground-based robotic telescope) captured first-ever optical images a gamma-ray burst at the very moment the burst was going off -- the "Holy Grail" for the hunters of these mysterious explosions, which occur with no warning, last only a few seconds, and produce more energy in that short period than the entire Universe combined. The split-second positioning of the telescope was made possible by the Gamma-Ray Burst Coordinates Network, a computer network that spreads the news about such bursts to several earth-bound and space telescopes. These six frames follow the burst as it brightens and fades.
(Credit: ROTSE team)
![[download 72 dpi GIF]](6_bursts.gif){kind=link}
This animation depicts two coalescing neutron stars forming a gamma-ray burst. Both stars where once active stars several times larger than our sun orbiting safely around each other. Upon their separate deaths, they blew off most of their matter. The remaining core, still more massive than the sun, collapsed to a sphere no wider than Philadelphia to form the neutron star -- a dense star with extremely strong gravity. As both stars became neutron stars, their intense gravity eventually degraded their orbits, sending them crashing into each other. Colliding neutron stars likely form a black hole. This is one way black holes can form and one theory to the origin of gamma-ray bursts.
(Credit: NASA)
![[download 72 dpi GIF]](smash.gif){kind=link}
For a closer look at gamma-ray bursts (spectra and scientific presentations), visit the Compton Gamma-Ray Observatory image gallery at http://cossc.gsfc.nasa.gov/cossc/outreach/images/grbs/
