Sun magnetic fields

[Murphy625]

My first post in this forum. I was a member of another forum that seems to be shut down and a quick google search pointed me here.

I have an amateur question.

Was reading about the sun's current conditions and they mentioned one of the sun spots has a "delta class magnetic field". How do they determine that from a distance? I've seen other articles about magnetic fields on stars and was wondering how they determine anything about a magnetic field without having a sensor in physical proximity.

Unless they can see plasma flowing along the lines, how can they determine anything about magnetic polarity or anything else?

This is probably a stupid question but I'm baffled by it. Spectroscopy, so far as I know, does not provide any magnetic field information.. or am I missing something?

Thanks,

[notFritzArgelander]

My first post in this forum. I was a member of another forum that seems to be shut down and a quick google search pointed me here.

I have an amateur question.

Was reading about the sun's current conditions and they mentioned one of the sun spots has a "delta class magnetic field". How do they determine that from a distance? I've seen other articles about magnetic fields on stars and was wondering how they determine anything about a magnetic field without having a sensor in physical proximity.
.


Unless they can see plasma flowing along the lines, how can they determine anything about magnetic polarity or anything else?

This is probably a stupid question but I'm baffled by it. Spectroscopy, so far as I know, does not provide any magnetic field information.. or am I missing something?

Thanks,

First of all welcome. Almost all of us are refugees from a forum that closed. If you'd like, please post an introduction here. viewforum.php?f=3 We're a pretty friendly and civil bunch.

Now to your question. Spectroscopy does provide magnetic field measurements. The magnetic field spilts spectral lines and the degree of splitting is proportional to the magnetic field strength. It is called the Zeeman effect and has been used since its discovery in 1896

https://en.wikipedia.org/wiki/Zeeman_effect

The application of the Zeeman effect to measuring magnetic fields on the Sun was pioneered by George Ellery Hale. There is a picture showing how this is done here: https://en.wikipedia.org/wiki/Zeeman_ef ... trophysics

Here's another example: http://prc.nao.ac.jp/extra/uos/en/no06/

[Murphy625]

My first post in this forum. I was a member of another forum that seems to be shut down and a quick google search pointed me here.

I have an amateur question.

Was reading about the sun's current conditions and they mentioned one of the sun spots has a "delta class magnetic field". How do they determine that from a distance? I've seen other articles about magnetic fields on stars and was wondering how they determine anything about a magnetic field without having a sensor in physical proximity.
.


Unless they can see plasma flowing along the lines, how can they determine anything about magnetic polarity or anything else?

This is probably a stupid question but I'm baffled by it. Spectroscopy, so far as I know, does not provide any magnetic field information.. or am I missing something?

Thanks,

First of all welcome. Almost all of us are refugees from a forum that closed. If you'd like, please post an introduction here. viewforum.php?f=3 We're a pretty friendly and civil bunch.

Now to your question. Spectroscopy does provide magnetic field measurements. The magnetic field spilts spectral lines and the degree of splitting is proportional to the magnetic field strength. It is called the Zeeman effect and has been used since its discovery in 1896

https://en.wikipedia.org/wiki/Zeeman_effect

The application of the Zeeman effect to measuring magnetic fields on the Sun was pioneered by George Ellery Hale. There is a picture showing how this is done here: https://en.wikipedia.org/wiki/Zeeman_ef ... trophysics

Here's another example: http://prc.nao.ac.jp/extra/uos/en/no06/

Thank you!

Now to look into why the spectral lines split as they do. You pointed me in the right direction!

[notFritzArgelander]

My first post in this forum. I was a member of another forum that seems to be shut down and a quick google search pointed me here.

I have an amateur question.

Was reading about the sun's current conditions and they mentioned one of the sun spots has a "delta class magnetic field". How do they determine that from a distance? I've seen other articles about magnetic fields on stars and was wondering how they determine anything about a magnetic field without having a sensor in physical proximity.
.


Unless they can see plasma flowing along the lines, how can they determine anything about magnetic polarity or anything else?

This is probably a stupid question but I'm baffled by it. Spectroscopy, so far as I know, does not provide any magnetic field information.. or am I missing something?

Thanks,

First of all welcome. Almost all of us are refugees from a forum that closed. If you'd like, please post an introduction here. viewforum.php?f=3 We're a pretty friendly and civil bunch.

Now to your question. Spectroscopy does provide magnetic field measurements. The magnetic field spilts spectral lines and the degree of splitting is proportional to the magnetic field strength. It is called the Zeeman effect and has been used since its discovery in 1896

https://en.wikipedia.org/wiki/Zeeman_effect

The application of the Zeeman effect to measuring magnetic fields on the Sun was pioneered by George Ellery Hale. There is a picture showing how this is done here: https://en.wikipedia.org/wiki/Zeeman_ef ... trophysics

Here's another example: http://prc.nao.ac.jp/extra/uos/en/no06/

Thank you!

Now to look into why the spectral lines split as they do. You pointed me in the right direction!

You're welcome. The quick answer is that the spin and orbital angular momentum of an electron make a tiny bar magnet which can interacts with an external magnetic field. That changes the energy of the electron orbit slightly. Before the magnetic field is applied some of the electron energy levels are the same. After it is applied the energy levels shift slightly.