White Light or Solar Continuum?

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nicspenceryork
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White Light or Solar Continuum?

Post by nicspenceryork »

Here's my first attempt at catching a sunspot in WL & Ha in the same session... which, in presenting them side by side, gave me the challenge of getting the 'right' yellow & orange colour, and now I'm stuck on some terminology and hoped you could help me understand?
I've heard the terms 'white light' and 'solar continuum' (SC) used interchangeably. I used a solar continuum filter with a Herschel Wedge to catch the 'white light' image and I'm wondering about the correct description. Would the title of the left image be 'AR12859 in WL' or 'AR12859 in SC' or 'AR12859 in WL with a SC filter' or am I just being a fusspot?!

ImageNS 20210823 WL1436 Ha1501 Sun AR2859 by Nic Spencer, on Flickr


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Re: White Light or Solar Continuum?

Post by dhkaiser »

Nice imaging and comparison. I use the term white light, although either will do. White light does seem to prevent the confusion you present.


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Re: White Light or Solar Continuum?

Post by EGRAY_OBSERVATORY »

Hi Nic,
I would suggest that "AR12859 in WL with a SC-filter on the HW' would certainly and simply explain enough..

If somebody wants to know more, then of course they can easily ask..

Two excellent images and thanks for sharing
Terry


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Re: White Light or Solar Continuum?

Post by DeepSolar64 »

Technically white light and continuum are the same but if you are using a narrowband 540nm filter it is not continuum but 540nm in the green part of the spectrum. But even though it is really 540nm green, in my posts I still label it “ WL “ because I am using the filter to enhance photospheric features usually seen in white light continuum. And it’s called a “ Continuum “ filter after all.

That’s my two cents worth.

James


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Re: White Light or Solar Continuum?

Post by DeepSolar64 »

In my observations I usually list the filter if it’s being used. For example, scope, wedge and filter.

Other bands can be used to accent photosphere features too as long as they are not ultra narrowband. Ha filters like those used for deep sky , Gband 430nm filters and K line filters. K line filters are said to do good for faculae. Ultra narrowband K line is of course Ca II K which shows lower chromosphere features.

Simple color filters can be of use too!

James


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Re: White Light or Solar Continuum?

Post by nicspenceryork »

Thanks Dan, Terry & James.
I’ll carry on with an overall ‘WL’ title then and list the equipment in the description. The ‘540nm in the green part of the spectrum’ detail helped the penny drop.
Much appreciated,


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Re: White Light or Solar Continuum?

Post by Montana »

That is an excellent image, but also an excellent question and made me think. My understanding of continuum is the continuous spectrum. Therefore, the surface of the Sun which emits a continuous spectrum. Therefore, the photosphere emits light across the spectrum and is called the solar continuum. However, the Baader Continuum filter helps you to resolve the granulations of the photosphere (solar continuum) more easily but is however a single wavelength of just 540nm :)

I need to go and look this up in a book :)
Alexandra


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Re: White Light or Solar Continuum?

Post by DeepSolar64 »

Montana wrote: Sun Aug 29, 2021 5:19 pm That is an excellent image, but also an excellent question and made me think. My understanding of continuum is the continuous spectrum. Therefore, the surface of the Sun which emits a continuous spectrum. Therefore, the photosphere emits light across the spectrum and is called the solar continuum. However, the Baader Continuum filter helps you to resolve the granulations of the photosphere (solar continuum) more easily but is however a single wavelength of just 540nm :)

I need to go and look this up in a book :)
Alexandra

Yep, technically it isn't continuum but 540nm. But....


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