Lunt 50 - Single Stack / Double Stack Comparison - 19th November

I've had my Lunt50 for a month or so now, but, at this time of year here in the UK it's never the best for observing with the low sun and less than ideal weather. I had first light proper last weekend, but in my enthusiasm lost all logic and reasoning and as a result never really ended up with an image I was 100% happy with through continually fiddling with the pressure tuner and double stack unit. Since then i'd given it some measured thought as to setting up the scope, and was ready for whenever the sun may reappear.

The weather forecast was not great for the weekend, but around Sunday lunchtime the clouds broke up a bit giving some transient gaps so I decided to setup and see if I could capture anything. Tuning the scope with some features on the disk was really easy compared to last weekends blank sun, and as a result I decided to get some images in single stack and double stack setup. I'm quite pleased with the performance in single stack, it reveals a lot more detail than my SM40 etalon would. SS image was at prime focus with the PGR CH3.

In previous threads and about the web there has been considerable discussion about the suitability of the LS50 as a scope for imaging in that people cannot reach focus. I struggled with the B600 that came with the scope, but the obvious solution was to use the Coronado BF15, this has much less optical length than the B600 and then reaching focus with a variety of configurations is possible. As an added benefit the BF15 lets through considerably more light than the B600 - I was getting 7ms DS 4ms SS with the B600, with the BF15 it is 1ms SS 3ms DS, quite a difference!

A side by side comparison of the black and white images:

Ha Full Disk - 12th November

It has been some time coming; the full disks I was getting from my trusty DS40 came to an end last year when a slip de-contacted one of the etalons.  I was able to recontact it but I was never completely happy with the results, there was banding and an uneven field of view.  I purchased a 50mm double stack etalon around this time as it was a bargain price, and then only very recently got round to buying the Lunt50 scope to go with it - once you double stack you never go back!  Totally the wrong time of year with a very low sun and poor weather, not to mention the demise into solar minimum, but it is nice to get the full disk overview in Ha.

Conditions couldn't really have been much worse, a direct northerly wind meant the temperatures at 500mB were very low, meaning much instability in the atmosphere.  Throw in the 'Cheshire Gap' effect where the weather blows in straight in between the high ground of North Wales and the Peak District funneling clouds over the West Midlands, and the clear blue skies were just a wolf in sheep clothing.  This time of year the low sun has dropped into the trees from my yard, and I only have a some brief windows of branch free viewing in between the foliage, so I was keen to make the most of things.  

I'm not used to the pressure tuner system, let alone the double stack, but I was pleased with this result that I got at prime focus (350mm) with the DS50.  The camera was the PGR Chameleon 3.  Not much to see on the sun at the moment, the filaments appearing to be associated with the long distant relics of active regions of old.  Not sure how much use I will get out of the scope this winter, another year passes and the trees on my souther horizon get bigger meaning less viewing time.  I will certainly try though if blue skies present themselves.

A Blank Sun To Start November...

The sun is very quiet at the moment, no spots at all, just a small relic patch of plage maybe indicative of an old active region?  Looking at the STEREO spacecraft data there is nothing on the way round in the week ahead either.  The joys of approaching solar minimum!

CaK Full Disk 27th October

Three observations of our star this month seems like a record based on the poor weather that has hampered observations for some time now, but, this morning it was certainly nice to first of all have clear skies and secondly be able to observe the sun.  Things are quiet currently as we descend ever closer to the bowels of solar minimum, but there are still the decaying active regions with small spots and associated plage of the active regions that have graced us for a third time around the sun.  The full disk was taken with the 40mm scope at ~560mm focal length with the home brew CaK filter and the PGR Chameleon 3 camera.  Not sure these spots will survive a 4th rotation but i'm confident we will see the plage again even if it is somewhat diminished than it is now.

AR12685 & AR12686 in Calcium Light - 27th October

A quick close up this morning of this pair of decaying active regions, now on their 3rd rotation of our star, not much other than a couple of dead spots and relic plage regions are all that are left now.  Pleased this image came out at all as was imaging with the 40mm scope somewhere up around 800mm focal length with the home brew CaK filter and PGR CH3 on an unguided camera tripod, quickly grabbing some frames to stack as the image raced across the field of view!

CaK Full Disk - 25th October

A sunny start to the day here in Anglesey, but I could see the next bands of clouds heading in from the south on Sat24 so was keen to try and get an image of our star in the frugal opportunities that have been presenting themselves in the second half of 2017.  I used the 40mm scope at 560mm focal length un-driven on a camera tripod with the PGR Chameleon 3 camera.  Given how this came out i'm pleased with the result, especially now as I type this a mere few hours after imaging the clouds have returned.  Taken with the home brew CaK filter.

A Deep Orange Sun, An Ex-Hurricane and Saharan Dust - 16th October

A curious and unique set of meteorological conditions gave a view of the sun today not often seen here in the United Kingdom.  Ex Hurricane 'Ophelia' was tracking northward in the Eastern Atlantic and due to make landfall on the southern coast of Ireland first thing on monday morning.   This had the effect of drawing up a warm source of tropical air from the Sahara Desert from North Africa.  This had been forecast for a couple of days over the weekend as temperatures in the UK rose to 25 celcius, some 10 celcius above the norm for this time of year.  Indeed on the sunday night a faint pinky sunset indicative of atmospheric particles scattering the longer wavelength red light.  The chart on the left shows the red line is the source of Saharan dust, whereas the blue and green plots have their origins from the mid Atlantic.  The red plot represents an air source within 500m of the surface whereas the green and blue plots air is some several thousand metres above the surface.  The plot below from the University of Greece shows the distribution of Saharan dust across Europe.  

The tongue of dust over the UK is been drawn up from ex Hurricane Ophelia drawing up the warm air from the south into it's cyclonic system.  The sky over Brierley Hill took on a peculiar Martian pinky tinge, looking very unusual, with the sun taking on a bright orange colour as the dust scattered red light in the atmosphere.  As the air source changed the sky and suns curious look changed back to normal almost instantly, and it's low height above the ground is shown by the pinky brown band on the horizon in the picture below.  If it was higher it would be more diffuse.  

Ghostly Clouds of Plasma - 8th October

The sun at first sight seemed deathly quiet today when I looked on GONG before going out to observe, but as is usually the case with our star it is just a case of looking in the right place and the right wavelength.  The air was surprisingly clear so I knew despite poor seeing looking in calcium wavelengths was going to be worthwhile.  Only the day before the active regions that had survived 2 rotations, producing the largest flares of this solar cycle rotated out of view over the limb.  However such large sunspots like that don't just effects in the photosphere, they are active in the chromosphere and above.  Today was a great example of this, despite the active regions being over the other side of the limb, the clouds of plasma that sit tens of thousands of kilometres above them were still visible silhouetted against the background of space.  The thin solar chromosphere, some 3000-5000km thick is visible with it's spicules on the limb. This shot was taken with the 40mm scope at 560mm focal length with the PGR Chameleon 3 camera and homebrew CaK filter.

CaK Full Disk - 8th October

It's been 7 weeks, not counting the eclipse, since i've been able to observe the sun.  Sunday dawned with some gaps in the clouds that were floating about, the sun is much lower in the sky, so waiting for it to clear the buildings I set up and went out to observe.  I knew that with so many surrounding clouds the seeing was going to be less than ideal, and indeed this was the case, so decided on the 40mm scope with the homebrew CaK filter to get an overview of the disk.  I knew it was going to be pretty blank with only a few regions of plage from relic active regions, but, where the large grouping on the western limb has passed over it was possible to see some towering clouds of plasma high above the active regions.  Click on the image for the full size view to get more detail.

Say Goodbye To Those Sunspots... 7th October

Sadly another weekend of poor weather means that i'm unable to make any direct observations of the Sun.  Fortunately NASAs Solar Dynamics Observatory is in orbit and way above all the clouds and weather.  It shows the sunspots that have survived 2 rotations now are once again about to pass over the western limb, whether they make it around again is anyone's guess, but if they do they will likely be considerably diminished in size.  Images from the STEREO spacecraft indicates there is nothing coming around the suns eastern limb any time soon, so, it looks like we may well return to a blank disk again for a while.

October Is Aurora Season - 1st October

For all the visual observers our star currently has several Earth sized spots visible in only modest equipment, alas these are dying active regions, and with their stable magnetic fields offer little in the way of promise for flares.  It is at these times we look at the sun in other wavelengths to see how our star can influence our planet.  In this image taken by the Solar Dynamics Observatory the large dark area just to the bottom left of centre disk is a coronal hole, this area on the Sun has open magnetic field lines, and as such is spewing plasma and charged particles out into inter planetary space.  This could well impact Earth as early as October 4th sparking displays of Aurora in northern polar regions.  October is statistically the second best month (after March) for seeing aurora.  Fingers crossed for great displays!

In The Shadow of Giants - 29th September

Despite a different numbering system when an active region rounds the solar limb, these are the same spots and active regions that put on a show with X class flares just 3 weeks ago.  Diminished and magnetically much quieter with stable magnetic fields, these sunspots hold little promise of solar flares however continue to put on a good show for observers world wide as we get ever closer to solar minimum.  Why are we getting these spots in the declining phase of the cycle?  Opposing bands of magnetic activity either side of the equator are violently interacting producing the activity we currently see.  How long will this last for?  Maybe another 11 months before we head into a solar winter before the next cycle starts in a couple of years...

Return of a Monster & Increased Chances of Aurora? 24th September

Our sun is quiet again in white light, with a medium sized but unassuming single spot visible that has little chance for flaring.  However looking down in the extreme ultra violet with the Solar Dynamics Observatory things show a different picture.  A large coronal hole extending from the suns northern polar regions is now geo-effective, which coupled with a co-rotating interactive region - the boundary between slow and fast moving regions of solar wind means there is a greater risk of auroral activity in the Earths polar regions.  

On the suns eastern limb (left hand side) there are coronal loops visible rotating around the edge of our star; these are from our monster sunspot grouping from a couple of weeks ago responsible for those huge x-class flares.  Will be interesting to see how it has developed on it journey around the back side of sun in the days ahead.

A Wolf in Sheep Clothing - 19th September

Just 2 weeks ago we had the largest solar flare for a decade and large active regions keeping solar observers pleasantly occupied in the declining phase of the solar cycle.  Now the face of the sun is virtually blank in white light, with only one small decaying active region.  You would be mistaken in thinking this means the sun is quiet; looking in ultra violet wavelengths with the Solar Dynamics Observatories AIA imaging rig reveals a large coronal hole is visible. These are the dark patches on the solar disk on the right, and their open magnetic field lines means that the solar wind flows freely from these regions.  As they are geo-effective it means the solar wind has been interacting with the magnetic field lines of our own planet and has been producing some great aurora in our polar regions.  It just shows that just because the sun might appear quiet in white light it doesn't mean it is actually being quiet!

New Active Regions - 5th September

Things have been busy of late not leaving much time for solar observing or updates to my website.  I have been out in the States on holiday to observe the total solar eclipse.  I've got a lot of pictures which at the moment i'm working through processing, initial results are promising and i'm working on an animation of the whole event along with a report.  In the mean time our star is showing a pleasing amount of activity with active large sunspot genesis with large flares.  This is a result of Band - Band interaction (after McIntosh et al) where bands of deep magnetic flux associated with the declining phase of the solar cycle get ever closer at lower latitudes towards the solar equator.  These bands have opposite magnetic polarity, opposite helicity, and, because they are in different hemispheres different Coriolis forces.  As a result of all these opposing factors we should anticipate that we have dynamic, fast forming and potentially violent active regions.  Which, is exactly what we see at the moment.  Incidentally, when you consider the Carrington event in 1859 this happened in the declining phase of solar cycle 10, at exactly the same point we are no in cycle 24, maybe we will get a repeat event this cycle?  Certainly worth looking out for!

AR12671 in Ha - 15th August

A new active region coming around the limb with plenty of small flaring activity.  The 203mm Airylab HaT was used but a mobile westerly air stream meant the seeing was never going to be the best.  I took a number of images and this one was the best of the bunch.  I was out early to observe and was surprised how much later the sun was now starting to rise as I realised we are closer to the autumn equinox than the summer solstice - seasons a changing!  

AR12670 in Ha - 10th August

It's getting near that time of year when only the best days are suitable for the large aperture of the 8" Airylab HaT here in Brierley Hills.  Despite taking some number of images this is the best one of the bunch and shows this decaying active region.  It should be on the limb this weekend so fingers crossed will put on more of a show.  Taken with the double stacked Quark at ~6m focal length with the PGR Chameleon 3 camera.

CaK Full Disk - 6th August

A clear if somewhat hazy morning today meant any solar imaging was going to be limited to the shorter focal lengths.  In the end it was a flat battery on the mount that brought an abrupt end to the session - a timely lesson in preparation!  Still, despite no power I was able to let the solar disk drift across the chip of the PGR Chameleon 3 camera to get this full disk in Calcium light with the 40mm scope at 560mm focal length and the home brew CaK filter.  The large spot associated with AR12670 should still be around for next weekend when it is the annual Solarsphere festival in Builth Wells. 

Old Active Regions Around Again - 31st July

Been away for a week or so, excuse being late in posting this up here, but finally got round to getting this animation processed.  Following a 2 week journey around the sun old active region AR12265 announced its return with a bright but dynamic prominence structure on the eastern limb as magnetic fields swirled around great waves of plasma.  For once this summer the sky had some clear breaks and I was able to get a view in.  The seeing was falling, but the view through the 8" Airylab HaT revealed the subtle changes in structure over the period of this 8 minute animation. The double stacked Daystar Quark was used with the PGR Chameleon 3 recording a cadence of 4 frames a minute for the animation.  Fingers crossed some clear skies return soon so that I can see what remains of it on the face of the sun.

CaK Full Disk 28th July

So far this summer i've been really unlucky with solar observing, either the weather has been bad or i've been tied up with work.  This morning there was some brief and unexpected clear skies so I managed a quick full disk in calcium wavelengths.  The sun is very quiet at the moment with no sunspots and only a couple of areas of plage.  Taken with the 40mm scope at 560mm focal length with the home brew CaK filter and the PGR Chameleon 3 camera.

6 Minutes in the Life of AR12665 - 8th July

The seeing was just about holding up for the 100mm of aperture of the Tal100R refractor this morning so I decided to go for an animation to see what this active region was up to.  This is just over 6 minute real time - before the clouds came back! with a cadence of 4 images a minute revealing just how quickly things change on our star.  Using a double stacked Daystar Quark and a 0.7x Baader solar telecompressor brought the focal length to a manageable 3 metres.  Using a PGR Chameleon 3 camera with 2x2 binning meant short exposure (3ms) times were possible to tame the seeing.

AR12665 With HaT in Poor Seeing - 8th July

I started off imaging with the 203mm Airylab HaT this morning, but the seeing was awful, and after shooting about 20 file runs this really was the best of them (and it's not very good!), so rather than pursuing this fruitless avenue I decided to back off to the 100mm scope instead.

Glorious Proms - 8th July

A lovely great big prominence visible this morning on the suns eastern limb.  Normally I don't both imaging proms but this one was too much to miss out on.  Taken with the Tal100R refractor at ~3000mm focal length with the Double stacked Daystar Quark and PGR Chameleon 3 camera using 2x2 binning.

Cak Full Disk 8th July

The sun is quiet at the moment bar the large single active region with multiple spots.  The seeing had really gone bad when this shot was taken, so much that I was only able to shoot at 400mm focal length with the 40mm scope using the home brew CaK filter and the PGR Chameleon 3 camera.

Growing Sunspots - AR12665

This active region has been growing quite quickly since rounding the limb a few days ago, as seen in this animation over 36 hours of SDO data.  So far it has not shown any signs of flaring, but hopefully this will change in the days ahead!

New Active Region Rounding The Limb - 5th July

Despite having to shoot through haze and ramp the exposure up, it was very easy to see just how dynamic this crown of plasma was as it spitted and changed form in real time on the laptop screen.  Since seeing it yesterday morning it is apparent there is a large single spot associated with it.  I needed to take a lot of images to find a best one, as the seeing and transparency weren't great, but, this came out ok.  Taken with the 203mm  Airylab HaT at ~6m focal length with the Double stacked Daystar Quark and the PGR Chameleon 3 camera using 2x2 binning.

The Scars of Spots Long Gone - 5th July

This may seem a fairly insignificant bit of the sun, but with its plage and filamentary structures marking magnetic fields, this area is the relic cores of some of the active regions that we have seen in the past couple of months.  The seeing wasn't great but shooting enough data and lucky imaging meant I was able to recover something usable.  Taken with the 0.2m Airylab HaT, the double stacked daystar Quark at ~6m focal length with a PGR Chameleon 3 camera with 2x2 binning.

CaK Full Disk - 24th June

An unexpected break in the clouds first thing allowed me to grab a quick CaK full disk this morning on a day when the forecast was for wall to wall clouds.  The seeing was really bad though, and even with the 40mm scope it was difficult to see sharp focus, I did briefly try with the 80mm to get a closer view of the spot, but I was wasting my time.  This was shot at 500mm focal length with the home brew CaK filter and the PGR Chameleon 3 camera.

AR12662 with the Airylab HaT - 18th June

This is my favourite image from the weekend and also one of the sharpest, taken with the 203mm Airylab HaT at a focal length of 7 metres, it is really starting to pull in some of the finer details caused by the magnetic field lines and their influence on the electrically charged plasma.  Taken with the double stacked Daystar Quark and Baader 0.7x solar telecompressor and the PGR Chameleon 3 camera using 2x2 binning to get 6.9um pixels and a short 3ms exposure time, which coupled with the 120fps capture rate works well in it's efforts to freeze the seeing.  

AR12663 with the Airylab HaT - 18th June

This angry little active region has been crackling with a number of smaller spots between the main bipolar group with many lines of swirling plasma molded by magnetic field lines.  Taken with the 0.2m Airylab HaT at 7m focal length using the double stacked Daystar Quark and PGR Chameleon 3 camera.

Plage with the Hat - 18th June

This region is typical of the sort of small scale features on a quiet sun that can be seen with the 8" Airylab HaT; with a regular size scope there would be little to see, but at nearly 7m focal length there is quite a bit.  The seeing was starting to go here, but this just about works.

Dark Filament - 18th June

This filament looked particularly dark on sundays sun, and I was pleasantly surprised when I looked at the final image the subtle detail that had been recorded.  The seeing must have been behaving at that point!  Taken with the 100mm Tal100R, Double stacked Quark running at f43, and a Baader 0.7x solar telecompressor to bring the focal length back to a more usable 3 metres.  The camera was the PGR Chameleon 3 using 2x2 binning to get a shorter exposure and larger pixels more suited to the focal length.

Active Regions with the Tal100R - 18th June

The 100mm Tal100R was putting on a good show with sundays solar activity as the heat of the day became too much for the seeing for the Airylab HaT, and with the wider field of view and lower resolution the resultant images were still nice and sharp.  There was lots to see, and with an f43 beam entering the double stacked daystar quark the contrast was high.  A nice set of images that I am pleased with!

CaK Full Disk 18th June

With temperatures up at 28c when I took this picture, the 40mm scope was all I was going to be able to use in the midday heat with the seeing conditions boiling away.  Fortunately this scope is impervious to all but the worst the atmosphere can throw at it, and, as a result I got a nice disk - 3 days in a row - surely a UK record 😆  Either way, at 500mm focal length and with the home brew CaK filter together with the PGR Chameleon 3 camera I got a nice full disk I thought!

AR12663 in Ha - 17th June

This is only quite a small region on the sun, 'merely' a dozen or so Earths across, but with the 0.2m Airylab HaT at nearly 9 metres focal length it is possible to get up close and personal with this tempest of plasma.  The image was taken shortly after 6am before the heat of the day destroyed the seeing conditions.  The sun looks angry and menacing at this scale.  The double stacked Daystar Quark was used along with the PGR Chameleon 3 with 2x2 binning to give nice large 6.9um pixels, 3 ms exposure time and a 120fps frame rate in an attempt to get the best out of the seeing conditions.

AR12662 in Ha with the Airylab HaT - 17th June

These 2 shots were both taken with the Airylab Hat, double stacked Quark, and PGR Chameleon 3 with 2x2 binning, the only difference being the wider field view used the Baader 0.7x solar telecompressor to give an effective focal length of just over 6 metres compared to the native focal length of nearly 9 metres using the quarks 4.3x telecentric instead of the Airlylab 2.7x telecentric.  The seeing wasn't perfect at this scale but it was good enough to get a couple of acceptable images.

Solar Activity in Ha with the Tal100R Refractor - 17th June

I have found a bit of an unusual setup that I quite like in this years solar season; my trusty 100mm Tal100R refractor works particularly well when my double stacked Daystar Quark is used in conjunction with the 0.7x Baader solar telecompressor and the PGR Chameleon 3 camera with 2x2 binning.  This unlikely combination delivers a f43 beam into the etalons for a contrast rich view, the solar telecompressor then brings this back to a more manageable 3 metres focal length, which on days when the seeing is too bad for the 0.2m Airylab HaT gives some nice views.  Our star was looking very fiery with this setup on saturday.