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The Question
(Submitted September 30, 1998)
I'm 15, but I can understand the answer in scientific terms.
How does a neutron star evolve to be a magnetar? Is it from the gravity
of the matters in the neutron star? Does a magnetar form from a supernova,
or before the star explodes?
The Answer
Hello,
This is an excellent question, and one which is at the frontier of
current research. First of all, nobody knows much about
magnetars since there existence was only recently suggested and
the observational evidence for them is even newer. As far as I
know the most likely scenario for their formation is as the
remnant from a supernova. This is the ultimate origin of all
neutron stars, and magnetars may be just the neutron stars which
are formed with the strongest magnetic fields. An interesting
observational fact is that all known magnetars appear to be
rotating quite slowly by neutron star standards, about once
every 8 seconds or so. This can be understood if they
are created with a much more rapid rotation rate, say once
every few milliseconds, because their strong magnetic fields
are expected to cause them to spin down very rapidly by magnetic dipole
radiation.
I don't know if there are other scenarios for
magnetar formation which are equally likely.
I hope this helps,
Tim Kallman for Ask a High-Energy Astronomer
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