Some Sun on a Saturday - 20th April

[markt]

The weather forecast had been promising good weather all week for saturday, and when I woke I could see the light coming around the edge of the curtains and knew they were right. Quickly outside and setup I wanted to get a good imaging run in...

I'll start off with the white light images. First the full disk that was taken at f6 with the 70mm frac, lunt wedge, continuum filter, and DMK31 camera.

wl full disk by Mark Townley, on Flickr

There are some spots visible, I wish there were more, but straight away i knew my target was going to be AR11726. Swapping the 70mm frac for the 100mm f10 I started off with a prime focus shot:

ar11726 f10 by Mark Townley, on Flickr

Surprised at how the seeing was holding up, the only thing to do was to crank up the focal length with the 2x barlow to take me up to 2000mm fl. However was trying something different, ditched the ND3 from the lunt wedge and replaced it with a moon filter I had lying around. This was ND 'not very much' but had the positive effect of meaning that I could image at 1/5000s exposure which did a fairly decent job of freezing the seeing very well...

ar11726 f20 2 by Mark Townley, on Flickr

Being a sucker for punishment I put in the 2.5x powermate meaning I was running at f25, or 2500mm fl if you prefer, however this was getting too much and is staring to soften up.

ar11726 f25 by Mark Townley, on Flickr

I'm going to look into getting some low value ND filters as these nice short exposures work well...

Next off to the Ha shots, and starting off with the full disk. The original images are much larger, so as ever encourage you to follow the flickr links through as there's lots more detail than shows up here:

ha full disk bw by Mark Townley, on Flickr

ha full disk colour by Mark Townley, on Flickr

These were taken with the 70mm PST mod at ~f7 and are 6 pane mosaics. I couldn't help but be drawn into the lovely prom that was visible. I don't normally do prom shots as don't seem to have much success with them, but this one has turned out ok.

prom by Mark Townley, on Flickr

Finally to the CaK shots; these were actually the first I took when the seeing was at its best early in the morning. Starting off with the full disk with the 100mm frac at f6, homebrew filter and ND less Lunt wedge as an ERF, taken as always with the trusty DMK31, this is a 6 pane mosaic... Again, original images are Much larger than this so follow the flickr links through to larger shots...

CaK full disk bw by Mark Townley, on Flickr

caK full disk colour by Mark Townley, on Flickr

AR11726 was crackling away in CaK wavelengths, so it was time to up the focal length to 1600mm and take a closer look:

ar11726 cak f16 by Mark Townley, on Flickr

ar11726 cak f16 crop by Mark Townley, on Flickr

ar11726 cak f16 crop colour by Mark Townley, on Flickr

Sitting and watching this active region boil and crackle away in real time on the laptop screen I decided to make an animation of it. Using a cadence of 20 seconds, this gave me somewhere in the region of just less than 600 frames per avi, of which I stacked the best 50 in autostakkert. This animation is 34 frames long and represents just over 11 minutes of time in the life of AR11726. Watch carefully, theres loads happening at the small scale; I particularly like the micro flare around the cluster of 3 spots at the bottom right, with the associated leaping arc of plasma. I also like the micro jet of plasma which shoots from the small spots at the top right...

cak-ani by Mark Townley, on Flickr

I actually have twice the amount of frames than i'm using, as CS4 kept crashing when I tried to load up 78 frames, however I think I have a fix for this I can have a mess around with later. Next time I do a CaK ani I think i'll drop the cadence down to 15 seconds as temporally there is alot going on!

I still have a few more shots to process from yesterday, and will get these done and up here later, but in the mean time hope you like these!

Mark

[Steve Ward]

Superb set there Mark . . .

[David Smith]

Crikey Mark. That must have been most of a days work. some fantastic images though.

[Bizibilder]

Very nice - its good to see the different wavelengths posted together for comparison.

[Montana]

They do look damn good on here!

:)

Alexandra

[DrRobin]

Very nice Mark. The CaK are fantastic, just loads of detail.

Robin

[sologuitarist61]

Beautiful images Mark