Thursdays Turbulent Star - 29th September

[markt]

Wow, 3 days in a row of clear blue skies and warm temperatures here in the UK, if this carries on for another day or so we will have hosepipe bans and water shortages

Seriouslly though, this is great for solar, the sun is not failing to impress and is putting on a turbulent, swirling show of activity. Lots going on again!

full disk lrg by Mark Townley, on Flickr

Taken with the usual setup, DS40 @ f20, DMK31.

Hope you like!

Get out there and observe our star if you can!

Mark

[couleurblue]

Beautiful and amazing.

Gordon.

[Black Knight]

Wow, that's another terrific image Mark. Great stuff!

[Merlin66]

VERY nice!

You've done us proud.

Well done.

[markt]

Cheers guys! appreciate the kind words!

[solarastro]

Hi Mark,

Great images,what is the Å of your filter?

Anthony

[markt]

Thanks Anthony!

I have no 'scientific' way of measuring it, however comparing to others images over the past couple of years I would estimate 0.45-0.5A. It's got decent contrast comparing to some other double stacks i've seen.

[Space Cowboy]

Outstanding solar image wow!

[Merlin66]

IMHO I'd say it's close to 0.5A - couple that with the surface resolution of the 40mm objective, the results are very good.

[markt]

IMHO I'd say it's close to 0.5A - couple that with the surface resolution of the 40mm objective, the results are very good.

Yeah, 0.5A sums it up pretty well. I have improved contrast over time by improving the mechanical interface between the 2 etalons and the scope itself - reducing banding effects that can be associated with double stack etalons to next to nothing levels, also loosing one of the ERFs improved contrast too. Next project (over the next week or so) is to replace the remaining 'NHS spectacle' Coronado ERF with a Baader equivalent which I expect to have a small but positive effect on contrast... Many small steps have a positive effect...

Thanks for your kind words folks, I do appreciate them!

[Montana]

Mark, I don't know how I will ever get results as good as you, well done!

I was hoping you might be able to help me with the flats question. I have tried many times now with my PST and I always get really bright white areas towards the edge of the picture which aren't there if you process without the flat in. This occurs in WL and Ha and I have almost given up hope. Do you have to defocus for every single area you take an image of? if so, I do give up as it takes me ages to get the focus right and then I am loath to defocus just for a flat.

Any help would be most welcome my NR are terrible with the DS and embarrassing!

Alexandra

[Beyond_Vision]

A really top notch image Mark. The detail is astonishing

Regards

Kevin