Monday, 30 December 2013
Sunday, 29 December 2013
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.
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!
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.
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
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.
Sunday, 22 December 2013
Saturday, 14 December 2013
Friday, 29 November 2013
Sunday, 24 November 2013
Wednesday, 20 November 2013
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
Thursday, 14 November 2013
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...
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...
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.
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.
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
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
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
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.
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
Thursday, 10 October 2013
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
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.
Tuesday, 24 September 2013
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.