As I am located in the New Forest, you can imagine that for some months of the year, particularly from late September until late November, condensation is a major problem in the dome. 

I have always used a product called “Water Eaters” from Lakeland Plastics [I prefer the name "Water Snake" but I guess the marketing people at Lakeland didn't] around the gap where the dome rotates.  This product is basically a sausage-shaped piece of fabric filled with some water absorbing substance [possibly silica-gel]. 

I always place these in the gap around the dome edge [on the inside of the dome] after an imaging session and they keep the ingress of water vapour right down.  Unfortunately, on their own they are still not enough! 

I had a problem with the Hyperstar a couple of years back where halos started appearing around bright stars after about half an hour or so of imaging.  At first I thought this was atmospheric water vapour.  After quite a bit of investigation I found out it was actually water vapour in the Hyperstar itself - not good! 

I got rid of the trapped water vapour by placing the Hyperstar in an oven at 40C for about an hour, but I clearly needed to also do something about protecting the observatory. 

To this end I bought a dehumidifier which now runs full-time in the dome.  I typically need to empty the water container every three days [roughly a gallon I suspect] throughout the year. 

I also have a thermostatically controlled greenhouse heater in the dome which is used to keep the dome temperature a few degrees above freezing during the winter months.

So far, these precautions seem to be working - I’ll find out this coming winter 

Have you had similar problems?  If so, how have you deal with them.  Drop me a line and let me know.

The last RGB image of the Veil nebula has been significantly improved by adding some H-alpha and some OIII narrowband data as can be seen in the accompanying image. 

However, the project has turned into an even bigger undertaking. 

I decided that I needed to get the nebulosity south of this region, so I embarked on a full two-frame Sky 90/M25C mosaic to capture the whole of the Veil complex.  I now only need the RGB data of the southern region (H-alpha and OIII already taken) in order to have an extremely deep and detailed image of the whole of the Veil.

The statistics make frightening reading.  So far I have taken 142 sub-exposures amounting to 27 hours total imaging time and a 1.7 GB file size.  The addition of the final RGB data is likely to take this project to over 30 hours total imaging time with a file size in excess of 2 GB. 

I am not sure I will undertake such a mammoth task again without the aid of the mini-WASP array!

The original image is on the left and the improved images (with H-alpha and OIII narrowband data) is on the right:

For me, the imaging object of Summer 2007 has been the Veil Nebula region in Cygnus.  This is to-date the greatest amount of data taken by me on one object, during one period - ever.  I’m not too sure I’ll be doing this again

This image comprises over 17 hours of total exposure time including 3 and a half hours of narrow band H-alpha data.  Over 8 hours of Hyperstar data for the Witch’s Broom region was also included in this image [these 8 hours were extra to the 17 hours taken on the Sky 90/M25C].

Processing time more than equaled imaging time on this one and Noel excelled himself here managing to squeeze out the very last traces of the Veil amidst a mass of overpowering stars - and quite a lot of Moon glow!

Why is the project only 90% complete? 

I have only just ordered an OIII filter [from Ian King imaging] to try and boost the blue/green regions you can see in the image.  If I can add this data in before the Veil moves into an unfavorable region of the sky [only a week or two away now] then I may finish this mega-project off this year.

We seem to have more than our fair share of power cuts in Brockenhurst and this has resulted in damage to both my computer and to the Celestron motor drive boards, both of which are very unpleasant experiences as you can imagine. 

I now use the Celestron Power Tank to power the Nexstar 11 GPS scope, basically a 12 volt rechargeable battery, and this isolates the scope entirely from the mains.  For the computer I now use an uniterruptible power supply [UPS] which is again based on a rechargeable battery which in turn powers an inverter. 

Finally, as I am also worried about glitches down the mains as well as the power cuts, I use Belkin “power surge” extension sockets which are designed to take any damaging spikes out of the mains supply. 

Touch wood - so far things seem to be working o.k.

I’d be interested to know if any one else suffers from similar problems and how you have dealt with it. Drop me a line and let me know.

In my last post I was at the point of deciding which refractors and CCD cameras to use.  I think I’ve now solved that dilemma!

Having gone through many combinations and permutations I am thinking the best solution for me is as follows: (more…)

As I said in the project announcement, living in the UK we have a major problem to contend with trying to pursue our hobby - the weather!  There are very few good clear Moonless nights to take those perfect images.  I have also compounded the problem by moving from a very fast (Hyperstar) imaging system that worked at f#1.85, to a much slower refractor-based system working at only f#4.5, i.e. six times slower. 

The problem I am trying to solve is how to get as much image data as possible in the short time allocated to us during the year.  One way of increasing the data is to parallel up the imaging, that is, to have several identical optical imaging systems all imaging the same object at the same time. 

(more…)

The name for this project comes from the Wide Angle Search for Planets or SuperWASP project.   As you can guess it is used for hunting exo-planets.  

If you look at the SuperWASP site you will see an impressive imaging array comprising 8 Canon 200mm f#1.8 lenses with their associated Andor CCD cameras all sitting on a massive torus fork mount - certainly very nice gear!

Living in the U.K. we have a major problem to contend with trying to pursue our hobby - the weather.  There are very few good clear Moonless nights to take those perfect images.  I have also compounded the problem by moving from a very fast (Hyperstar) imaging system that worked at f#1.85, to a much slower refractor-based system working at only f#4.5, i.e. six times slower. 

I’m going to tackle this problem piece by piece and I will be posting details of my thoughts in the mini-WASP Array category.  You can also see a list of the posts below:

• Update on the mini-WASP deep-sky imaging array, December 23rd, 2008
• The mini-WASP array morphs into the NIP, November 6th, 2008
• mini-WASP Array Project - Part 3 - The Framework , December 8th, 2007
• mini-WASP Array Project - Part 2 - A Likely Solution, August 7th, 2007
• mini-WASP Array Project - Part 1 - The Problem, August 2nd, 2007
• mini-WASP Array Project, July 10th, 2007

I hope you’ll keep reading as I learn about what is needed and my experiences of putting together such an exciting piece of equipment.

I’m thinking ahead about the deep-sky object that I will concentrate on for the short summer nights.  I am really impressed with the image of the Veil nebula on Davide de Martin’s Skyfactory site where he has processed this superb image using Palomar POSS II data.

I think I’d really like to give this one a good try, however that field of view (FOV) of 4.2 x 4.4 degrees would mean a 2-frame mosaic with the Sky 90/M25C combination, and I’m not too happy about spending that much time on just one object, especially with short evenings.

However, Steve Cannistra has also imaged the Veil region with a set up that has a very similar field of view to mine and although it doesn’t get the whole of the region in the frame, it still makes a very impressive image.

Taking all things into account, I will try to get a very deep single-frame image of the veil region using the one-shot camera and the usual Hutech IDAS light pollution filter. 

I know from the previous work I carried out on the Witch’s Broom region of the veil with the Sky 90/SXV-H9C combination that the one-shot is fine for this purpose. 

The only thing that I don’t know is how good (or not) the one-shot will be at picking up the faint stuff between the Eastern and Western veil regions.  I guess the only way to find out will be to image the thing this summer

I’m going to be posting more about the Veil Nebula project and you can follow my progress in the Veil Nebula Category or by clicking on the links below [which also happen to be from the Veil Nebula category]:

• The Veil nebula - reloaded, March 20th, 2008
• The Veil nebula in Cygnus - a supernova remnant, March 18th, 2008
• The whole of the Veil nebula in Cygnus, March 17th, 2008
• The Veil Nebula in Cygnus Imaging Project: Almost, but not quite..., September 8th, 2007
• The Veil Nebula in Cygnus Imaging Project: 90% Complete, August 31st, 2007
• Summer 2007 Imaging Project: The Veil Nebula in Cygnus, January 11th, 2007

The diagram from Cartes du Ciel will give you an indication of where the Veil Nebula is in the night sky:

Finally!  I have managed to eradicate the one minus point of having the Nexstar and motor drives in the dome!

I upgraded the motor drives from version 30.30 to version 40.40 (download available from the Celestron site).  Amongst the many benefits of the upgrade was that the telescope tracking is now entirely silent - HOORAY!