Astronomy Picture of the Day
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October 23, 1995
Gamma rays are more than 10,000 times more energetic than visible light.
If you could "see" gamma rays, the night sky would seem very different
indeed. The bright object in the centre of the false colour
gamma-ray image above is quasar
3C279, a nondescript, faint,
starlike object in the visible sky. Yet,
in June of 1991 a gamma-ray telescope onboard NASA's orbiting
Compton Gamma Ray Observatory unexpectedly
discovered that it was one of the
brightest objects in the gamma-ray sky.
Shortly after this image was recorded
the quasar faded from view at gamma-ray energies. Astronomers
are still trying to understand what causes these enigmatic
objects to flare so violently.
Another quasar, 3C273, is faintly
visible above and to the right of centre.
Tomorrow's picture: A Total Solar Eclipse
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