White Light 1st to 14th January

[Qualia]

One of the joys of this January has been to wake under blue skies and have an endlessly changing horizon, each day bringing a new and different sun.

The first week witnessed AR 2253 suddenly come into existence, a huge sunspot wider than Jupiter. By the second week another sunspot AR 2257 had come onto the scene and was reported to have erupted around the 13^th, this time producing a pulse of extreme UV radiation that spilt over the Indian Ocean’s upper atmosphere.

Although nothing so detailed as an image, I hope the sketches go some way of showing what has been happening this last fortnight.

All the sketches were made using the same gear:

TV 76mm

Herschel Wedge, ND 3.0, Variable Polariser & Continuum

B.G. Ortho 9mm

[jetstream]

Fantastic sketches Qualia, somehow you have managed to show granulation in a sketch, this is remarkable.

[nightfisher]

Qualia, an excellent set of sketches very nice indeed

[Pig]

Excellent pictures Rob  Is it true that granulation is only visible in white or green light ?  and in Ha it is dark mottles that are seen on the surface.

[jabeoo1]

Excellent pictures Rob  Is it true that granulation is only visible in white or green light ?  and in Ha it is dark mottles that are seen on the surface.

 I am pretty sure granulation resolves in white light and the Ha & CaK lines.  Green filters will enhance the visibility of granulation & faculae.  

I have not had the opportunity to compare the Ha view with a white light view, although the Ha view is rich, it may appear darker than what people expect.

(Edit: I just noticed your Lunt 60 in your signature strip Pig   )

I sometimes feel like I am looking at something that has a photographically negative appearance in Ha.

Defining the seeing & transparency conditions based on what you can see in terms of granulation is useful.  

The following was information found inside J Jenkins book Observing the Sun:

>5 arc sec = Granulation not visible.

3-5 sec arc = Granulation sometimes visible.

1-2 sec arc = Granulation appears blotchy.

<1 sec arc = granulation resolved.

Lovely sketches Rob !  What media & materials are you using ?

Cheers

[Qualia]

Thanks for the replies, gentlemen. It's been another nice morning and perhaps there's a slim chance I'll be able to finish the month without interuption from clouds. In general, granulation is always apparent, not always all over the Sun but certainly in moments of stillness it is clear and discernable.

Jabe, the process of sketching couldn't be simpler:

Paper, a circle and shade in the circle with a Chamois cloth 'dipped' into graphite (typically use 2B).

4B the umbra, blending stub for the penumbra.

Faculae is the trickiest part for it would be too time consuming to sketch exactly what you see. I imagine the best way would be to rub out thin streaks from the shaded circle, but that in itself would be quite difficult. So to cut corners, I simply draw them in with a pencil.

For granulation blotch in more pencil shade from the shammy cloth.

After that, simply scan the image into the computer and use something like Gimp 2 or Paint.net to cut the circle and paste it to a black background. You may find it necessary to tweak brightness, for sometimes the image comes out a little too faint.

From start to finish, that is, setting up scope, sketching and packing up generally takes no more than 30 minutes.

[Pig]

Jabeoo,

I was given the book you mentioned as an Xmas present  I have read some of it but not in depth enough as yet, what I have read is very interesting and informative.

I read the comment about granulation and white light in an article recently, and it made me re-consider what it was that I could see in Ha

I totally agree with your point and when I physically look through my Ha & WL scopes side by side both surface patterns are similar, albeit very much more detailed in Ha. So I will take it the article was examining white light

[Stu]

Fabulous sketches Rob, really good to see.

The TV76 really does deliver superb views doesn't it?