everyone of us knows what
a magnet is. But I myself have only recently heard of magnetars. To
be clear: there are no known magnetars anywhere near to be a danger
to us. So, whatever you'll read now and may get you scared: don't
panic!
I understand very little
about physics and astronomy, to tell you exact details anyway, so it
can't get too scary today. Nevertheless I want to give you an idea of
what I understand what a magnetar is. In the universe there are
planets, meaning objects that move around, like the earth for
example, going round itself as well as around the sun. Planets don't
shine. The sun however is not a planet, but a star and stars do
shine, but don't move. Stars like the sun have much energy, which at
some point is used up. Some of you may certainly have heard the word
supernova. That's what happens to a star when the energy is used up:
the star shines one last time really bright, while it explodes and at
least the shape and everything it had until then is destroyed.
Sometimes the things left over after a destruction of the star with a
certain strength of a magnetic field, turn into a neutron star, a
magnetar.
Magnetars are relatively
small stars, just about 10 to 30 km (12 mi) in diameter (which is
about the size of a smaller city). They turn around themselves in an
incredibly fast time. A rotation period is the time a planet takes to
turn around itself to get to the starting position again. The
rotation period of the earth is 24 hours. Magnetars are often found
with partner stars. Wikipedia has as one of the rules to call a
single star a magnetar, among other things, the rotation period of 1
to 12 seconds! Sure enough something small of 10 to 30 km in diameter
can rotate around itself in a faster time than the earth anyway.
Still I find 1 to 12 seconds for a rotation period pretty fast. Even
though they're relatively small, magnetars have the mass of 40 times
that of the sun!
The dangerous thing about
magnetars for one thing are the x-rays and the gamma rays, which come
up every now and then. X-rays aren't healthy for us anyway, which is
why they try not to make a person take x-rays too often. Gamma rays
are the shortest wave length we know so far and they're the most
dangerous, too. Even if they don't kill us right away, they change
the molecules and that kills us in the medium-term, similar to
tumours. But not only that. When a magnetar is as far away from the
earth as the moon, it's magnetic field would pull your coin money out of
your trouser pockets. A magnetar half the distance of the moon and
the earth would destroy the magnetic strip of your credit card
forever. I don't even want to think any further about people with a
pacemaker or other metal objects in them...
I can't tell you much more about
magnetars actually. Like I said, I don't know much about physics or
astronomy. I just find it fascinating to have learned about stars,
which are just about the size of a city, but have considerably more
mass than the sun and a strong magnetic field so it can pull your
coin moneyout of your pockets. I'll tell you a little bit more about
magnets and magnetic power anyway... in another blog post.
sarah
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