Wednesday, 30 March 2011

TiO Near Full Disk - The Filter That Tames Seeing!

TiO Full Disk lrg, originally uploaded by Mark Townley.

Living here in the West Midlands our skies are criss-crossed by the flight paths of planes. All trans-Atlantic flights to and from London Heathrow all pass overhead in a NS / SN direction, and Birmingham International Airport is not too many miles to the east of me, so that part of the sky is riddled with planes there. This has the effect of destroying the 'seeing' conditions making solar imaging boil away.

I have tried a Baader Solar Continuum filter, and on days of good and better seeing this is an excellent object optically. However more times than most the seeing just blurs the sun, even with this narrowband filter.

Here the 706nm 'TiO' filter really comes into its own. Longer wavelength light is much less affected my the turbulent skies of bad seeing and this is really evidenced in this series of pictures.

On the laptop screen the spots, faculae and granulation really locked on instantly, and didn't bounce around as with the shorter wavelengths. The detail was immense!

This near full disk shot was taken with the 70mm frac @ f6 and DMK31 camera.

Oh, this filter and it's holder including shipping was less than £20 - a true bargain!

AR1183 TiO Wavelengths

ar1183-TiO-70mm-f11 lrg, originally uploaded by Mark Townley.

A closeup of this new active region with the 70mm frac @ f11. The shot is oozing with detail in the spots, granualtion and faculae.

AR1176 in TiO Wavelength

AR1176-TiO-70mm-f11 lrg, originally uploaded by Mark Townley.

A closeup of AR1176 using 70mm frac @ f11. The image is a bit harsh in its tone, however this is caused by the reasonably thick layer of haze. The 706nm filter cut right through this as if it wasn't there though, and apart from the left and right ends of the histogram on the capture software being dragged right in, reducing the dyanamic range somewhat, i'm quite happy with how this turned out! Really looking forward to 'proper' clear skies to be able to fully evaluate this filter!

Tuesday, 22 March 2011

Major Eruptive Prominence 19th March

one shot montage lrg, originally uploaded by Mark Townley.

The montage shows the expansion of a major eruptive prominence that ocurred on march 19th. Observing early in the morning the simple prominence at that time was showing all the signs that the solar magnetic field holding it together was going to collapse. Shortly after 11.20ut the magnetic field lines snapped releasing huge amounts of plasma out into space.

This image was taken with a Coronado SM40 @ 800mm fl with a DMK31 camera.

By 12.15ut the prominence had expanded so much that it was on the limits of visibility, however by now it was nearly a 1/3 solar diameter in size. This is the largest prominence visible since april 2010.

Prom Montage 19th March

Prom montage lrg, originally uploaded by Mark Townley.

This set shows the expansion of todays eruptive prominence. Click on the image to view full size!

Prominence Animation 19th March

one shot animation, originally uploaded by Mark Townley.

Shows the expansion of this eruption over about an hour...

Wide Angle Big Prom & Disk 19th March 12-03ut

This prom really expanded fast. Here it has expanded about a quarter solar diameter in half an hour - that by my reckoning is an expansion velocity of some 700000km/hr!

A rough and ready image that needs to be reworked later!

Huge-Prom 11-53-55ut 19th March

A very quick, rough and ready capture of the eruptive promince from saturday. Need to rework this image at some point as looking back it's quite rough!

Argon Sun - AR1175 19th March

Argon Sun 127mm f9 lrg, originally uploaded by Mark Townley.

This shot was taken with the 127mm refractor @ f9, and as such has a slightly faster exposure. Coupled with the greater resolution of this particular scope over the 70mm means more detail is visible. A promising filter!

Argon sun 488nm 70mm f11

argon sun 70mm f11 lrg, originally uploaded by Mark Townley.

Compared to the continuum image of the same area, this area is quite a bit lower in resolution. This is due to the lower transmission value of the argon filter, only about 50%, as a result there is quite a bit more smearing visible - known as 'seeing smearing'. This can be combatted by using a lower density primary filter on the scope as opposed to the solar wedge, and as result get the exposure time considerably shorter. By doing this I think imaging at this wavelength will yield some interesting results - so, watch this space!

Argon sun full disk 488nm

Argon sun full disk lrg, originally uploaded by Mark Townley.

At this wavelength and with this setup the sun is fairly indistinguishable from a continuum image. The PL130M camera works well with this filter and the wedge due to its high sensitivity compared to the DMK31. The 'sharpness' slider on the camera was set too high and as a result there is some vertical banding visible.

My Best White Light Shot Yet!

AR1175 70mm f11 lrg, originally uploaded by Mark Townley.

Taken of active region 1175, this was imaged with the 70mm refractor at f11 using the Lunt solar wedge, Baader continuum filter and DMK31 camera.

Really pleased with the way this has turned out, the disk is oozing with detail in terms of the granulation, plenty of faculae visible also. The spot region is really sharp in this image. If I can get all my whitelight images looking like this then things are looking up!

CaK Full Disk 19th March & Fixing Astigmatism

cak full disk lrg, originally uploaded by Mark Townley.

Following the realignment procedure of the prism in the CaK PST to reduce / remove astigmatism from this lovely scope I was keen to re-image the sun at these wavelengths. The image of the sun here shows that while quality is significantly improved on those of last year, looking carefully at the southern polar regions there is still some 'smearing' visible. I am aware of my fix of realigning the prism on the PST by using sticky back velcro is by no means a permanent method, however it has served as a good test of the rationale behind the fix.

When the focus on the PST is racked all the way in this forces the prism to push against the interior of the black box body of the unit. Normally this would not be an issue if the the interior was square, however it is not, there is a sloght recess around the eyepeice holder area; as such, when the prism pushes against it causes the prism to be pushed out of it's square position.

So, now, it's the fix part 2. I intend to reopen the box, and either fit a spacer in the recess so that its surface sits flush with the rest of the interior of the PST, or, resit the prism on the block that fixes to the focus thread so that when the focus is racked all the way in the prism doesn't touch the interior body of the unit. Not sure which method will work the best, but will be sure to check both out and report back!

Wednesday, 16 March 2011

Full Disk Ha Mosaic 13th March

Full Disk Mosaic DMK31, originally uploaded by Mark Townley.

One more picture to add to sundays series... Forgot I had taken these 2 images with the DMK31 and DS40 @f10.5. It's come together reasonably well though I need to practice more with the joins on these mosaics. Todays sun (16th) shows a pretty blank solar disk compared to this one, and looking at NASAs STEREO website it looks set to remain fairly inactive until later in the coming weekend. Fortunately though the weather forecast at this stage looks good for the weekend, so, fingers crossed, I should be able to get some more imaging and viewing in then! If i'm lucky my TiO (titanium oxide) filter should have arrived and i'll get the opportunity to try it out...

Tuesday, 15 March 2011

Argon Sun - 488nm 13th March 2011

ar11166 488nm 127mm lrg, originally uploaded by Mark Townley.

For sometime now i've been contemplating the use of different filters in solar astronomy. I already have a Baader solar continuum filter, this is a 10nm wide bandpass filter centered on 540nm wavelength, this type of filter gives contrasty almost narrowband views of the sun in visible light. I know others have achieved good results in whitelight by using a deep red filter - basically the longer wavelengths are less affected by seeing, so something that has potential in the UK!

Out of curiosity for sometime now i've wondered what can be achieved at different wavelengths, then through talking to my buddy Apollo in the States started to look at filters that are used for lasers and microscopy. I settled on a 488nm filter with a 1-2nm bandpass - this gives cyan coloured views of the sun in 'argon' light.

Through the eyepeice the view was dimmer than with the continuum filter, but this is to be expected with the narrower bandpass. Granulation was larger and more diffuse than with the continuum filter, but the really obvious thing was the plage - this was really bright, almost like in the CaK images. This pic was taken with my 5" refractor with Lunt solar wedge and the 488nm filter. I think it has potential! When this image was taken the sun was only about 10deg above the horizon, with the sun high in the sky the results could be alot better!

I'm going to explore this more, however in the mean time have a 706nm laser filter on order - this is a filter in the titanium oxide band, and is also the same sort as used by the Big Bear Solar observatory. If my cameras can work at this long wavelength in the Infra red then I have hope. Watch this space for updates!

Monday, 14 March 2011

CaK Full Disk 13th March 2011

Cak full Disk lrg, originally uploaded by Mark Townley.

If you look at my previous CaK images on this blog you will see there is a smearing of the image. This is due to astigmatism - the penta prism that is in the 'black box' part of the PST is misaligned, a common problem with Coronado Ha & CaK PSTs. I had tolerated this for sometime, however decided that with a new year of solar observing starting in earnest it was time to act.

Opening up the black box to reveal the penta prism, it can be seen it is out of alignment by some several degrees - this may not seem a huge amount but it is more than enough to cause smearing of the image snapping pics. The penta prism is connected to a mounting block by means of a soft sticky goo - the sort of stuff that fixes cd's to the cover of magazines. I had contemplated replacing this with another glue, however had visions of getting this all over my fingers and then all over the faces of the prism - which would have been bad - very bad, as it would have meant the prism was a write off.

I ended up deciding on heavy duty sticky backed velcro strips - I figured once I had these in place I could locate the prism in postion, and then , after imaging, if this was not optimum relocate it again.

Seems this method works as the image above shows. It's the sharpest CaK image i've got to date and i'm really pleased to be honest.

AR1166 & 1169 Closeup in CaK

ar11166 cak lrg, originally uploaded by Mark Townley.

With the CaK PST performing at its full potential again it meant I could do a bit of closeup imaging. This was taken at f19 with the DMK31 camera.

AR11166 Flaring in CaK

ar11166 flaring cak lrg, originally uploaded by Mark Townley.

Whilst doing my CaK images I was surprised to se ar1166 start visibly flaring away in real time on my laptop monitor, so I snapped an image. This has caused some talk on the cloudy nights solar forum where it has been said people have not seen flaring in CaK wavelengths before, so needless to see i'm pleased with this pic!

Ha Full Disk 13th march 2011

Full Disk Ha lrg, originally uploaded by Mark Townley.

This shot was taken with the double stacked 40mm Coronado etalon mounted on a 420mm fl scope, used with a barlow nosepiece to give an focal ratio of about f16. The camera was the PL130M, and while this is quite a quirky imaging device I think i'm slowly getting the hang of it. This is a 'one shot' exposed to show the disk features and the prominences around the limb simultaneously. Unfortunately there weren't any large proms, however the overall image was quite interesting.

Ha Close Up Sunday 13th March 2011

active sun ha lrg, originally uploaded by Mark Townley.

An interesting western hemisphere on the sun today with large active regions 1166 & 1169 heading closer to the limb. A smaller non named active region follows these two which showed three small spots in white light. In the southern hemisphere a couple of large contrasty filaments could be seen. Magnetic field lines can be seen sprawling around the active regions.

Tuesday, 8 March 2011

AR11165's Departing Crown

AR11165-Departing-Crown, originally uploaded by Mark Townley.

Looking like the crown produced when a stone is dropped into a pond, AR11165 spits and splutters out plasma as it passes over the limb. This has been a fascinating active region to watch over the past several days - lots going on! Today was possibly the icing on the cake! As a bonus a small filaprom snakes slowly over the limb beneath it. Taken with the usual setup - DS40 @ f19 DMK31.


AR11166-AR11169, originally uploaded by Mark Townley.

Possibly the last day of good weather for me for a while - Atlantic weather rolls back into the UK again from wednesday! The seeing conditions weren't too good this afternoon but I did manage to get this snap: Behemoth active region 11166 is seen in the bottom right of the frame, with smaller ar11169 following it mid frame. Both active regions show intense magnetic fields surrounding them. To make the perfect frame there was a lovely diffuse prom on the limb.

DS40 f19 DMK31

Monday, 7 March 2011

AR11165 Departing 7th March

AR11165 Departing, originally uploaded by Mark Townley.

The sky was clear and blue all day for a change here in Brierley Hill today - days like this are rare, we don't get too many like this in a year! As soon as I could get away from work I did - however by then the sun was dropping low in the sky, transparency was excellent, however seeing was terrible - boiling away in the eyepiece and quite obviouslly on the laptop screen.

This is the only picture that was really usable from this afternoon. AR11165 is showing there is still life in it as it gets ever closer to the limb - spitting and crackling away. This was taken with my DS40 @f19 DMK31.

Ha Full Disk 6th March 2011

After what seems like weeks of grey and dreary weather, the high pressure that is sat over the UK at the moment finally gave way to properly clear blue skies. I was keen to image under excellent transparency, even if seeing was poor with boiling skies. There was plenty going on the solar disk with several large active regions as can be seen. Though, unusually, today the sun was remarably devoid of prominences. All of the active regions could be seen to be showing minor low level flaring. This shot was taken with Coronado DS40 etalons on a 420mm fl ota.

White Light Full Disk 6th March 2011

WL-full-disk-small, originally uploaded by Mark Townley.

I'm continually amazed at the performance of this little 70mm f6 refractor and the Lunt Solar wedge used in conjunction with the Baader solar continuum filter. This image was taken with the PL130M, and in order to image needed 2 neutral density filters in the optical train to bring the exposure to an acceptable level. Detail is very promising. I'm really looking forward to being able to use the wedge with my 5" frac as the year goes on, which will give increased resolution at a longer focal length.

CaK Full Disk 6th March 2011

Cak-Full-Disk-Colour-Small, originally uploaded by Mark Townley.

A very active sun today in CaK wavelengths. The image is showing signs of the astigmatism inherent in the prism of the CaK PST (this is the blurring at the bottom of the disk). I will be attempting to fix this in the week ahead by reseating the prism on it's mounting block. A visual inpspection reveals that the prism is currently out of alignment by several degrees. Removing and then reseating it should hopefully remedy this issue. The effect is less noticeable at longer focal lengths, although image quality here (in the following images) is diminished by atmospheric dimming due to the low altitude of the march sun.

AR11164 Ha

AR11164-small, originally uploaded by Mark Townley.

DS40 f19 DMK31 6th March 2011

AR11164 CaK PST

ar11164-cak-sml, originally uploaded by Mark Townley.

Active Region 11164 in Whitelight

ar11164-wl-small, originally uploaded by Mark Townley.

70mm f11 lunt wedge

AR11165 Hydrogen Alpha

ar11165-small, originally uploaded by Mark Townley.

DS40 f19 DMK31 06/03/11

AR11165 CaK PST f19

ar11165-cak-sml, originally uploaded by Mark Townley.


AR11165 White Light

ar11165-wl-small, originally uploaded by Mark Townley.

70mm f11, lunt solar wedge, continuum filter, DMK31 camera.

AR11166 Ha

ar11166-small, originally uploaded by Mark Townley.

Taken with DS40 @f19, DMK31. The active region was flaring mildly at the time this picture was taken.

AR11166 CaK

ar11166-cak-sml, originally uploaded by Mark Townley.

Taken with CaK PST @f19, DMK31. 6th March 2011.

Active Region 11166 In Whitelight

ar11166-wl-small, originally uploaded by Mark Townley.

Taken with 70mm refractor @f11 with Lunt Solar Wedge and solar continuum filter. DMK31 camera. 6th March 2011.

Thursday, 3 March 2011

Ha Sun 02/03/11

A quick full disk shot after I got home from work yesterday. Little in the way of proms and the main feature on the disk was AR11146. This shot was taken with the DS40 @ f10.5 with the PL130M camera. Whisst this camera has a larger chip size allowing the full disk to be framed in one shot it seems to lack the detail, contrast and dynamic range of the more expensive but smaller chipped DMK31 - shame really! Ideally I would use (and want to save up for!) a DMK41... The line across the full disk is a result of me shoting through the overhead wires - one of them was in shot. Still, nice with the longer days to be able to image the sun more - not long till British Summer Time starts which will extend my solar viewing window in the evenings after work still further :)

Active Region 11164

AR11164 (large), originally uploaded by Mark Townley.

Yesterday afternoon cleared up nicely under the high pressure we have over the UK at the moment, and despite the realtively featureless disk in Hydrogen Alpha light, in white light the obvious feature was active region 11164. This is a large and complex spot group that has been crackling with minor activity. The sun was only several degrees above the horizon when this shot was taken, and as a result of atmospheric dimming the exposure was 3 times longer than i've used previously. The shot was taken with my 70mm f6 refractor with the Lunt Solar Wedge and continuum filter. A 2x barlow was used on the nosepeice of the DMK camera resulting in an efl of ~820mm. Given the low altitude of the sun i'm pleased with the image as it shows solar granulation quite well aswell as the brighter plage areas. Finergs crossed for morfe clear skies today!