CaK Spectra

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p_zetner
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CaK Spectra

Post by p_zetner »

Here are some Ca K spectra taken at different locations on the disk. (01 October 2013 Sun)



I was surprised to see the central bright peak at the sunspot. Then I consulted Zirin and, of course, it's expected! The two K2 features coalesce there.

Cheers.
Peter.


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Re: CaK Spectra

Post by marktownley »

Very interesting stuff indeed Peter! I'm impressed! :)


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Re: CaK Spectra

Post by Cschur »

Excellent! Now repeat with helium with those dark faculae...

Chris


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Re: CaK Spectra

Post by Derek Klepp »

Now that gives me some night time reading, I find the more I read Zirin the better my understanding becomes.


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Re: CaK Spectra

Post by Montana »

Excellent :hamster: I wish I could do this sort of thing :bow: :bow: :bow:

Alexandra


Nick

Re: CaK Spectra

Post by Nick »

Is it me or is there a very slight blue shift on the plage?


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Re: CaK Spectra

Post by swisswalter »

Hi Peter

thank you very much for the insight, very informative and interesting


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Re: CaK Spectra

Post by p_zetner »

Thanks Everyone.

Chris: You're setting me a challenge! The He D3 line is very faint on the disk (It's just barely visible on the BASS2000 solar spectrum).

Nick: The plage spectrum was shifted, by eye, into alignment with the disk spectrum. If I were to take great care in aligning a whole set of spectral lines (outside of CaK), I might be able to look for a line shift in CaK but, as these spectra were processed, there's no way of meaningfully analyzing a line shift. What's interesting is the CaK lineshape itself changes as you go from disk centre (mu=1.0) to limb (mu=0.0). This is noticeable on these spectra if you overlap them and is in keeping with the general behaviour of Fraunhofer lines - broadening as you approach the limb. (The three spectra presented in the picture have been offset with respect to each other by a unit of 0.1 on the vertical axis.)

Derek: Honestly, my eyes start to glaze over if I read too much Zirin. His is an extremely comprehensive book, but I find the writing and explanation somewhat opaque with excess detail in some places and not enough detail in others. Also, the indexing is nearly useless. Fewer words, more diagrams, more math would be my preference. I've ordered Foukal's "Solar Astrophysics". I hope it's better.

Cheers.
Peter.


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Re: CaK Spectra

Post by marktownley »

I've ordered Foukal's "Solar Astrophysics". I hope it's better.

Let us all know how you find it :)


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Re: CaK Spectra

Post by p_zetner »

Hi Mark.

Got my copy of Foukal's "Solar Astrophysics" yesterday and, at first glance, it looks great. Not as extensive a collection of phenomenology as Zirin but not as scattered a discussion either! Foukal gives very clear, methodical explanations of what's presented (looks like it might be used as a course textbook - doesn't shy away from mathematics). For me, it's quite a step above Zirin in quality. I'm interested in learning more about lineshapes and line formation. It looks like I'll be learning a lot from this book.

Cheers and Happy New Year.
Peter.


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