Astronomers with X-ray eyes

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Astronomers with X-ray eyes
If you could see the world through X-ray
sensitive eyes you would only see extremely hot
things, hotter than one million ºC and with
incredibly short wavelengths. You wouldnt be
able to see your friends or Dorking Halls or Box
Hill, but if you took a journey up through the
Earths atmosphere and looked out into the
Universe a whole new sky would become visible.

X-ray
Visible
Radio Visible
X-ray
X-ray
Temperature increasing
M31 the Andromeda Galaxy
Orion
X-rays cannot penetrate through the Earths
atmosphere so astronomers have to send up
satellites to be their X-ray eyes. European
astronomers spent many years designing and
building the latest X-ray satellite to go into
orbit. It is called XMM-Newton and has been
looking at hot objects in our own Galaxy and in
distant galaxies since its launch in December
1999. It has already pointed to over 200 X-ray
sources and has made possible some important
scientific discoveries.
Many different types of objects in space
generate X-rays. Here are just a few
The most powerful X-ray sources we know of are
quasars. These are galaxies powered by a massive
black hole at their centres. Quasars are so
distant that we only see a single point of light
from Earth. This is a picture of what a quasar
may look like at it centre
V
Stellar coronae, the outermost layers of a
stars atmosphere, are hot enough to emit X-rays.
Here is a picture of the Sun in X-rays
Most stars exist in pairs and orbit around each
other they are called binary stars. When one of
the pair is a hot white dwarf star we can see the
system in X-rays. Here is an artists impression