Zeeman effect in sunspots?

[David Strange]

Can anyone tell me whether it is possible to image the splitting of the spectral absorption lines of a sunspot with an Alpy spectroscope?

Thanks

David

[Dr Andrew Smith]

The resolution is way too low. I would estimate you nee R ~ 27000 (assuming I did the sums right).

Regards Andrew 

[Robin Leadbeater]

Indeed. The splitting in the solar spectrum needs much higher resolution than the ALPY.  It seems it is possible though with a LHIRES stopped down and using a very narrow slit giving ~R=43,000 (Christian Buil, near the bottom of the page)

http://www.astrosurf.com/buil/polar3/index.html

Cheers

Robin

[Robin Leadbeater]

Another (marginal) observation of the Zeeman effect by Buil at R~30000.  Also of doppler broadening/profile distortion due the to Evershed effect

http://www.astrosurf.com/buil/lhires2_sun/sun250904/obs.htm

[David Strange]

Thanks for that. i am researching Lockyer’s work on sunspots when he projected the sun’s image on to a screen with a slit in it, over which he positioned a sunspot. With his spectroscope receiving the light of the spot, (I guess it was his 7 prism one) he noticed that the spectral lines were widened. This was years before Pieter Zeeman’s discovery of the splitting of spectral lines due to magnetism and Hale’s observations linking sunspots and magnetism.

David

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