How Do Distant Stars Cause Solar Flares?

[Ivan Seeking]

Solar flares that scorch Earth's atmosphere are commonplace. But scientists have discovered a few each year that are not like the others: they come from stars thousands of light years away

http://science.nasa.gov/headlines/y2003/12sep_magnetars.htm?list955064

 

[zoobyshoe]

Ivan,

I noticed this article at Physics-
Posts as well and a couple of
related ones.

It discusses these "magnetars"
which are the most densly magnetic
of all celestial things.

The sun's solar flares are complex
magnetic phenomena, it explains.

It is not immediately obvious to
me what is generating the magnetic
fields in the sun and other stars?

Here's what I know that is pre-
venting me from understanding how
a star could have a magnetic
field:

When you heat a piece of ferro-
magnetic metal to a temp. above
its Curie temp. (Not very
hot in star terms) it loses all
ability to generate or respond to
a magnetic field. The molecules
become too energetic to maintain
the orderly arrangement needed for
their combined magnetic fields to
add up to a general one.

Although I'm sure there are vast
quantities of charged particles in
a star, it would seem the intense
heat would prevent them from ever
organizing to the point where a
magnetic field could be generated.

How do stars generate their magnetic fields?

 

[Mr. Robin Parsons]

Good Question ZOOBYSHOE!

 

[Ivan Seeking]

Originally posted by zoobyshoe
Ivan,

I noticed this article at Physics-
Posts as well and a couple of
related ones.

It discusses these "magnetars"
which are the most densly magnetic
of all celestial things.

The sun's solar flares are complex
magnetic phenomena, it explains.

It is not immediately obvious to
me what is generating the magnetic
fields in the sun and other stars?

Here's what I know that is pre-
venting me from understanding how
a star could have a magnetic
field:

When you heat a piece of ferro-
magnetic metal to a temp. above
its Curie temp. (Not very
hot in star terms) it loses all
ability to generate or respond to
a magnetic field. The molecules
become too energetic to maintain
the orderly arrangement needed for
their combined magnetic fields to
add up to a general one.

Although I'm sure there are vast
quantities of charged particles in
a star, it would seem the intense
heat would prevent them from ever
organizing to the point where a
magnetic field could be generated.

How do stars generate their magnetic fields?

Well, I can make a best guess. Even though we may have highly chaotic motion on the local level, from the more distant perspective we still get a large scale average motion. This can be seen in the latest movies that show the sun's rotation. So, just as we can consider the motion of any particular electron in a wire as nearly random, we can still observe the large scale average motion of many electrons in a wire as a steady current with a fixed magnetic field.

 

[Tyger]

Originally posted by zoobyshoe
Ivan,

I noticed this article at Physics-
Posts as well and a couple of
related ones.

It discusses these "magnetars"
which are the most densly magnetic
of all celestial things.

The sun's solar flares are complex
magnetic phenomena, it explains.

It is not immediately obvious to
me what is generating the magnetic
fields in the sun and other stars?

Here's what I know that is pre-
venting me from understanding how
a star could have a magnetic
field:

When you heat a piece of ferro-
magnetic metal to a temp. above
its Curie temp. (Not very
hot in star terms) it loses all
ability to generate or respond to
a magnetic field. The molecules
become too energetic to maintain
the orderly arrangement needed for
their combined magnetic fields to
add up to a general one.

Although I'm sure there are vast
quantities of charged particles in
a star, it would seem the intense
heat would prevent them from ever
organizing to the point where a
magnetic field could be generated.

How do stars generate their magnetic fields?

There are two ways of producing magnetic fields, by using moving charges, and by some form of spontaneous sysmmetry breaking, as in ferromagnetism. The currnt wisdom! is that the fields are produced by the so-called dynamo effect, but my vote is definitely for spontaneous symmetry breaking.

 

[Ivan Seeking]

Originally posted by Tyger
but my vote is definitely for spontaneous symmetry breaking.

Interesting. Why?

 

[LURCH]

Originally posted by zoobyshoe
Ivan,



How do stars generate their magnetic fields?

This is a question we have yet to answer. You might want to look in on the doin's of a Dr Daniel Perry Lathrop, who's currently attempting to model the Earth's magnetic field. His models are based on the dynamo principle. If he is successfull, it will be good supporting evidence that the stars generate their fields this same way.

I did not see any predictions in the link as to how much matter a star might blow off in such an eruption. If anyone has some thoughts regarding this, it would help me work through a model of Solar System formation I've been toying with.