Monday 30 December 2013

Solar Shadow Rings - 29th December

The sun hangs low among the trees and rooftops around mid winter and this if often more of a hinderance than anything else, however today I noticed a very curious effect I have never seen before.  I could see a strange ring patter created by the branches rapidly appearing and disappearing on the laptop screen.  I initially thought this was similar to when there is an eclipse in progress and light shining through the leaves on the trees creates crescent shaped shadows, however I quickly dismissed this as there are no leaves this time of year, and if a pin hole projection effect was happening then there would be circles projected not annuli as in the animation above.  Then it dawned on me, the Coronado SM40 etalons I use have a central obstruction that project a shadow on the image of the projected circular disks through the trees.  Well, that's my theory anyway, if anyone knows any other possibilities please feel free to comment on this post.  Either way i'm happy with the result and have ended up photographing something i've never seen before! 

Sunday 29 December 2013

Ha Full Disk 29th December

Ha-Full-Disk-Colour1 by Mark Townley
Ha-Full-Disk-Colour1, a photo by Mark Townley on Flickr.

The sun was certainly low in the sky today, and in the crisp air and deep blue sky looked very picturesque. However looking in the wavelength of hydrogen light details on the sun just pop into view that can't be seen in normal light. This shot was taken with the Coronado DS40 at f10 with a DMK31 camera. It's easy to see all the activity is focused in the suns southern hemisphere corresponding to the this dual hemispherical peaking we seem to be having this solar maximum.

CaK triband Closeup 29th December

About as close as the low sun and turbulent seeing would let me get on a cold frosty winters morning. This image was taken with the triband ERF, DS CaK filter and 70mm frac at f10 with the DMK31 camera. A good result from a setup that shows much promise!

CaK Full Disk Triband ERF 29th December

CaK-triband-colour by Mark Townley
CaK-triband-colour, a photo by Mark Townley on Flickr.

This was the first outing for my new triband ERF from Oliver Smie at Beloptik; I installed it in the dew shield of my 70mm f6 refractor where it was a perfect fit. Using my using rear mounted homemade CaK filter setup the first thing that struck me was how much shorter the exposure time was probably due to the ERFs transmission of 70% compared to the usual 5% of the solar wedge I was using as a filter. Optical quality is spot on, and later in the year I plan to do a more thorough review at the 3 wavelengths it operates at. I'm pretty pleased with this image - even given the smudge at the bottom of the disk is the branch of a foreground tree.

CaK Sun - 29th December

caK sun bw by Mark Townley
caK sun bw, a photo by Mark Townley on Flickr.

After weeks of unfavourable conditions I was able to end the year on a solar high. After spending the day rebuilding the helical focus assembly on my Coronado SM40 tube assembly I switched the Ha filters for my homemade double stacked CaK filter, seeing was awful first thing on this frosty sunday morning so used a 0.5x focal reducer to try and tame the seeing a bit. It seems to have worked and i'm pretty pleased with this result!

Friday 27 December 2013

Sauðárkrókur Aurora - 31st October

During late october we visited Northern Iceland for the week, and naturally I was quite keen to photograph the aurora, especially as we are around solar maximum and any activity should be reasonably good.  On the 31st of October we stayed overnight in the small town of Sauðárkrókur on the North coast of Iceland.  With a population of only just over couple of thousand people this was a quiet town.  On sunset that evening I was watching the aurora and weather forecasts, and for once both seemed pretty good.  At nightfall I went for a walk around the town to try and find a dark corner free from lights, however for such a small town what it lacked in people it made up for in street lights - they were all over the place; big bright streetlights.  With the border of the town the mountains on one side and the Arctic ocean on the other there simply was nowhere to go.  I tried my usual dark sky tricks and went to the rocks at the top of the beach that formed sea defences (right hand side in the pictures above), however these rocks were there for a reason as big waves crashed over the top of them with an intimidating ferocity.  

I tried aiming the camera higher in the sky to cut out the foreground horizon, but this made no difference at all; the temperature was well below freezing and the crashing waves a hundred metres to the north of me were throwing mist up into the air at an annoying rate.  All the way through this imaging session I used my trusty Canon 350D at iso800, 30 second exposure with a Sigma 10-22mm lens, at 10mm f4 all mounted on my manfrotto tripod.  I tried reducing both the exposure and ISO, and while this reduced the brightness of the skyglow it also reduced the brightness of the aurora,  which is definitely not what we are trying to achieve.  
Turning the camera to the part of the town with the least number of streetlights had a marginal improvement on sky conditions, however the foreground was still too bright for my liking, and as was also pointing in a westerly direction it meant that auroral activity was also reduced.  Despite it being quite an active auroral display with curtains of green dancing all over the sky these just weren't happening where was needed for a good picture.  Taking the land rover out to a dark spot in the mountains wasn't an option either as we'd had a drink with our meal earlier on in the evening.  Then the answer came to me from the skies as I could see a huge auroral curtain was going to pass pretty much straight overhead - point the camera vertically upwards thus getting the darkest part of the sky with the least light pollution.  
It worked!  The above animation is made up from 24 30second exposures, spanning a time frame of just over 12 minutes in total.  The auroral curtain was moving across the sky from east to west at the zenith, and was shortly followed thereafter with clouds!  However to get this I was more than pleased as i'd pretty much written off any chances of recording anything that night.  Hopefully when we revisit in february there will be clear skies again and the aurora will put on a good show for us!

Sunday 22 December 2013

Some Late Solstice Sunshine 22nd December

I made this animation late this sunday afternoon, and it typifies to me my luck with solar imaging at winter time:  a low sun, behind the trees and passing clouds making the view hazy.  Still, it is significant image taken a day after the winter solstice, the nights are now getting shorter again, the days longer, and with each passing day the sun gets ever so slightly higher in the sky.  Here's hoping 2014 is a great year for solar astronomy!

Saturday 14 December 2013

December CMEs & UK Cloud

The cloudy weather continues here for me in the UK, with any sunshine normally when i'm at work and cloudy skies on a weekend - the only time I can observe with the low sun that we have in december.  Despite the weather here on Earth the Sun keeps putting on a show; on December 12th, a pair of magnetic filaments on the sun erupted in quick succession between 0300 UT and 0630 UT. The explosions hurled a pair of coronal mass ejections (CMEs) into space. SOHO recorded the clouds racing away from the sun at approximately 1.1 million mph (500 km/s).  Although neither explosion was squarely Earth-directed, the two clouds could deliver glancing blows to Earth's magnetic field on Dec. 14th or (more likely) the 15th. NOAA forecasters estimate a 40% chance of polar geomagnetic storms when the clouds arrive.

Friday 29 November 2013

Death of a Comet?

Given that Comet Ison came within a 1 solar radii diameter of the surface of our star, experiencing temperatures in excess of 5000 fahrenheit, it is little surprise when watching this animation that it seems to evaporate away significantly reducing in it's brightness.  Whether anything has survived and come out of the other side of the sun remains to be seen, but it is highly improbable Ison will end up being the brightest comet for some significant time as some media sources have reported.  In the days ahead observations shoud give a clearer view of what has gone on...

Sunday 24 November 2013

Comet Tails Blowing In The Solar Wind

NOAA forecasters may well be giving a low chance for solar flares at the moment, but flares or not the solar wind endlessly keeps blowing.  This image was taken by the STEREO-A spacecraft from outside Earths orbit.  It shows the solar wind blowing from right to left, with Comet Encke approaching the sun from the top left corner of the image downwards, and Comet Ison entering the frame from the mid left.  The influence of the solar wind on their tails is very easy to see in this very unique image.  The STEREO spacecraft was launched in 2006 and has been providing views of our star since then.  This video gives some great information about its mission:

Wednesday 20 November 2013

X-Class Flare Hurls Off CME Into Space - 20th November

With all the recent solar activity it was only a matter of time before another flare occurred.  On 19th november at 10.26ut departing sunspot AR11893 crackled with a massive X-1 flare.  While the explosion was not squarely directed at Earth this flare did affect our planet, with the UV flash creating a wave of ionisation in the upper atmosphere over Europe, Asia and part of Africa with a brief high frequency radio blackout occurring over the poles.  The explosion hurled off a huge CME however this is not aimed at our planet.  

Sunday 17 November 2013

Chance of X-class Flares - 17th November

Cloud may well have returned to the UK again, but the Sun is crackling with plenty of activity: Sunspot AR11897 has evolved into a sprawling archipelago of magnetic islands with more than a dozen dark cores scattered across 350,000 km of solar "terrain." This complex region has a 'beta-gamma-delta' magnetic field that harbors energy for X-class solar flares, and it is directly facing Earth. Any eruptions from AR11897 this weekend would likely be geoeffective. NOAA forecasters estimate a 60% chance of M-class solar flares and a 15% chance of X-flares.

Thursday 14 November 2013

ar11890 & Prom - 10th November

ar11890 prom ha colour by Mark Townley
ar11890 prom ha colour, a photo by Mark Townley on Flickr.

This widescreen mosaic was taken with the 100mm PST mod at 2000mm fl with the DMK31 camera. This was a lovely turbulent area of sun to view!

ar11890 ha 10th November

ar11890 ha colour by Mark Townley
ar11890 ha colour, a photo by Mark Townley on Flickr.

Lots to see with the monster spot when viewing with the 100mm PST mod.

ar11893 ha colour 10th November

ar11893 ha colour by Mark Townley
ar11893 ha colour, a photo by Mark Townley on Flickr.

Lots of activity visible in this shot taken with the 100mm PST mod at f20 with the DMK31 camera.

New Active Region Ha 10th November

new ar ha colour by Mark Townley
new ar ha colour, a photo by Mark Townley on Flickr.

The new active region that was coming over the limb seemed pretty quiet!

Ha Full Disk 10th November

Ha Full disk colour by Mark Townley
Ha Full disk colour, a photo by Mark Townley on Flickr.

Taken with the Coronado DS at f20 with the DMK31 camera , there's plenty happening on our star at the moment to see!

ar11890 cak 10th November

ar11890 cak colour by Mark Townley
ar11890 cak colour, a photo by Mark Townley on Flickr.

To me, the main benefit of the double stacked CaK filter is the real increase in contrast it brings. These CaK images are pretty much 'naked' - they were shot with gamma neutral (100) on the DMK31 camera, and the only post processing is sharpening and colouring. They were taken with the 100mm at f10 with the homebrew CaK filter using the Lunt wedge as an ERF. The only problem with this setup is at longer focal lengths and with a lower altitude sun, the exposures are getting too long; this is going to be remedied very soon as I have a triple band ERF enroute from Germany. This will be mounted sub aperture in the Tal 100mm refractor, and with a Moonlite focuser fitted should become an ultimate solar telescope...

ar11893 cak 10th october

ar11893 cak colour by Mark Townley
ar11893 cak colour, a photo by Mark Townley on Flickr.

The 1.5 angstrom bandwidth of the double stack CaK filter comes into play as shown in this image with the prominences and surge jets just about visible. Given that this image was taken in november, only just over a month away from the winter solstice, the result is pretty impressive. I think images taken in 6 months time, when we will have the sun much higher in the sky, will show prominences quite readily. Now, I just need to take this setup several thousand metres up a mountain and the views would be indiscernible from those taken from space...

CaK full disk 10th November

CaK full disk colour by Mark Townley
CaK full disk colour, a photo by Mark Townley on Flickr.

I seem to have got the reflection issue with the double stack CaK filter sorted out (the reflection is out of the fov!) - as a result there is a lot more contrast visible. Infact, if you click on the full disk image and view it in Flickr it is quite easy to see the prominences at the 8 o'clock position. Bear in mind that this image was taken with the 40mm ota at f20 with a DMK31 camera and the results are very promising. I may look at getting a 2" Baader U-filter (venus filter) to use as a full aperture ERF with this scope as a way of reducing the thermal load on the Baader K-line filter that is currently being used as a sub aperture ERF.

ar11890 WL 10th November

ar11890 wl colour by Mark Townley
ar11890 wl colour, a photo by Mark Townley on Flickr.

This monster active region had been responsible for several X-class flares prior to me taking this picture, however at the time of this shot it was just breaking up and showing signs of a light bridges forming. This image is my favourite whitelight from the series shot on the 10th november. Taken with the 100mm frac at 2000mm focal length, Lunt solar wedge, solar continuum filter and DMK31 camera.

ar11893 WL 10th November

ar11893 wl colour by Mark Townley
ar11893 wl colour, a photo by Mark Townley on Flickr.

These spots look great as they round the limb! Taken withe the 100mm at 2000mm focal length, DMK31.

New Active Region 10th November

new ar wl colour by Mark Townley
new ar wl colour, a photo by Mark Townley on Flickr.

100mm, 2000mm fl, solar continuum filter, Lunt wedge.

ar11887 10th November

ar11887 wl colour by Mark Townley
ar11887 wl colour, a photo by Mark Townley on Flickr.
Taken with the 100mm @ f20 with the DMK31, this active region had a lovely display of plage visible.

WL Full Disk 10th November

WL full disk colour by Mark Townley
WL full disk colour, a photo by Mark Townley on Flickr.

It's typical, it's northern winter and the sun is low in the sky and has really started to bustle with activity. Contrails hindered this full disk a little, but the end result is passable and gives a good overview. Taken with the 40mm @ f20 DMK31.

Friday 8 November 2013

Charlie Bates Solar Astronomy Project Annual Fundraiser

Here at the Charlie Bates Solar Astronomy Project we are having our annual fundraiser - this is to raise the funds for the 1000's of solar glasses, scopes and outreach events that have shown over 80,000 young people the sun over several continents worldwide.  

So far we have raised over $11000 towards our target of $15000, however there is still 3 weeks left to donate money towards this good cause.  For each donation of $100 you will receive a raffle ticket for the fantastic pressure tuned Lunt 60 solar telescope above.  However any amount, no matter how small you wish to donate will be going towards achieving  and hopefully exceeding our target.  If you have not donated towards this I would strongly urge you - If you have received free solar glasses then it is the Charlie Bates Solar Astronomy Project that has paid for them.

Donations can be made online using paypal here!

Tuesday 5 November 2013

Iceland Aurora - October 30th

I have visited Iceland a number of times to view the aurora borealis, the interaction of the charged particles of the solar wind and our Earth's upper atmosphere.  This causes the dance of ribbons of colour across the night sky.  However despite several visits in recent years bad weather has not allowed me to make any observations since 2010.  This October we returned to Iceland for a weeks holiday and needless to say looking out for the northern lights was a priority.  We had travelled to Myvatn in Northern Iceland and were staying in a wooden lodge; the Icelandic weather service were promising clear skies around midnight, and this was also confirmed by a local who said he was going at midnight with a view to photographing them.  This was good enough for me, so at midnight I ventured out in the -12c freezing landscape.  The first thing that struck me was how clear the sky was and just how many stars were visible - Jupiter seemed nearly bright enough to cast shadows.  I looked to the northern sky and could see a faint green arc, slightly brighter than the milky way.  I knew activity wasn't high, the Kp index at the time was at 1 on the scale which is basically next to nothing, however this was the first time in 3 years I had a chance so you have to take what is on offer.  I used my regular aurora photographic setup; a canon 350D on iso800 shooting consecutive 30 second exposures, the lens was a Sigma 10-22mm at 10mm f4.  I managed 77 minutes of continuous exposures before the camera battery started to give up the ghost, and as this was now after 2am I was getting rather cold and tired.  At several times throughout this session I could see the rays and streamers shooting up from the horizon, and the ripples and waves moving along the green arc.  It has taken some work to get the time lapse presented in such a way that the subtle details are not lost through image compression, and as a spin off i'm hopeful some of this new learned technique should lend itself to producing higher resolution solar animations - however the proof of that will have to wait until the sun returns higher in the sky next year.

Sunday 3 November 2013

Ha Full Disk 3rd November

Ha Full Disk colour by Mark Townley
Ha Full Disk colour, a photo by Mark Townley on Flickr.

Our star is crackling with solar flare energy at the moment with several large active regions currently on view. Throw in some great filaments and prominences and this makes for a fine sight in the shorter days of November. This image was taken with the Coronado DS40 at f20 with the DMK31 camera.

DS CaK Full Disk 3rd November

DS CaK colour by Mark Townley
DS CaK colour, a photo by Mark Townley on Flickr.

The sun was getting low and the sky was getting hazy late on sunday afternoon when I took this shot, and despite it being a little softer than I like, for an early november image I don't think it is too bad. Tilting the notch filters with respect to each other (and the baader K-line) has sorted out the issue with ghosting that I was getting with previous images. I'm happy with the contrast i'm getting from this setup now, and are really looking forward to the spring when the sun starts climbing higher in the sky again...

Saturday 26 October 2013

A Busy October Sun - Sadly No Shots!

The sun has really picked up in activity over the past couple of weeks with several M-class and X-class flares hurling material off into space towards Earth.  Sadly at this time of year i'm limited to when I can image only on weekends, and these in october have either been cloudy or i've had other commitments.  Well this increase in solar looks set to continue which is good news from my perspective as i'm off for a weeks aurora hunting in Iceland.  Stay tuned for any updates of this fascinating interaction of the solar wind on our planets magnetic field and atmosphere!

Thursday 10 October 2013

DS CaK - 6th October

DS CaK by Mark Townley
DS CaK, a photo by Mark Townley on Flickr.

It wasn't until late on the sunday afternoon when I managed to get a very brief shot of our star using the DS CaK filter on the 40mm at f20, the sun was only about 10 degrees above the horizon, given that there was passing high cloud the outcome isn't too bad. I did a bit of experimenting with the double stack CaK unit; angling one of the CaK notch filters with respect to the other with a view to throwing the reflection doesn't work. This creates an offband image lacking in finer detail. By far the best result is with the filters parallel faced, this produces the most detail however with a slight haziness as a result of an overlapping reflection / ghost. I think I may have to look at placing a suitable blue filter between the 2 cak units as a possible solution to this ghost image - another experiment to try, shame it is heading towards winter which hinders progress! Still, very promising results!

Sunday 29 September 2013

Double Stacked CaK Disk - 29th September

My newly constructed double stacked CaK filter is showing itself as a keeper.  Compared to a single stack CaK unit the plage is much brighter compared to the background disk and super granulation is much more evident and apparent over the entire disk.  More interestingly is that proms are much more apparent than in the single stack filter.  Today a surge prom in the 2 o'clock position was easily see, even in this image taken with the 40mm at f20.  There are tantalising hints of the spicule layer also being visible.  Given that this shot  was taken in poor seeing conditions with a low altitude sun, it does bode for even better results when conditions are ideal.  There is still work to do; a 'ghost' is visible superimposed on the right hand side of the disk, but this should be relatively easy to either remove or throw out of the field of view.  In short, i'm really pleased with this filter, I just wish I had got it 6 months earlier this year!

ar11850 & Surge Prom - DS CaK 29th September

ar11850 CaK by Mark Townley
ar11850 CaK, a photo by Mark Townley on Flickr.

There was a lovely surge prom visible today using the double stacked CaK filter. The faint CaK spicule line can also just about be seen on the limb. It seems that double stacking in CaK makes the prominences much easier to see compared to the single stack images. I was pushing things today with the low altitude sun, with this shot being taken with the 100mm at 2000mm focal length with the DMK31 camera, but this image is just about usable... It definitely has much promise for when the sun is higher in the sky.

ar11850 & ar11846 DS CaK 29th september

ar11850 ar11846 caK by Mark Townley
ar11850 ar11846 caK, a photo by Mark Townley on Flickr.

A medium scale shot of the departing active regions visible on the suns disk today taken with the 100mm at 1000mm focal length with the DMk31 camera.

Ha Full Disk - 29th September

The sun may not have many large active regions at the moment, but the disk is far from being bland.  Lots of filaments are visible in this image taken with the Coronado DS40 at f20 with the DMK31 camera.

Tuesday 24 September 2013

CaK Full Disk 22nd September

ds cak full disk colour by Mark Townley
ds cak full disk colour, a photo by Mark Townley on Flickr.

Even on a relatively quiet day on the Sun as it was as we passed into autumn there is still plenty to see in CaK wavelengths. This was another outing for the double stack CaK filter, which had been redesigned in its configuration to remove the reflections and ghost images that were present when i first set it up. It is performing very well now with only minimal ghosting at the bottom of the disk which should be fairly easy to remove with a bit of tilting. This was taken with the 40mm @ f20 with the DMK31 camera.

Ha Full Disk - 22nd September

DS Ha full disk bw by Mark Townley
DS Ha full disk bw, a photo by Mark Townley on Flickr.

Some intermittent september sunshine allowed me to shoot this full disk using the DS40 at f20 with the DMK31 camera.