Littlefoot Elegance Photo User

Astroforum rund um die Astro-Elektronik


Saturday, 28 April 2007

The old Cosmicshed Observatory

Now gone to pastures new, but still fondly remembered.

Here is the roll-back observatory that gives this site its name. I has now been replaced by a new dome observatory.

I first built the decking from leftover materials from the obligatory garden deck. This gives a reasonably steady platform for the shed to roll on and gives some isolation from the concrete hard-standing.

The shed is to a standard tongue and grooved board over timber frame design. I included a layer of plywood between the frame and boards for additional rigidity and weather protection. The external grade chipboard roof is covered by roofing felt. The door is made from T&G floorboards. As the shed has no floor, I included corner bracing at the base.

The shed rolls back on four three inch fixed casters from a local DIY store. They run fairly true without the need for grooves, which I thought could be a trip hazard.

The shed is remarkably sturdy. I had planned to provide some way to secure it to the deck when not in use, but it has stood up to strong winds this Autumn.

With the shed rolled back there is room for a PC etc between it and the pier. My observing chair fits snuggly in the shed giving me a little protection from the elements.

Originally designed for a fork mounted LX200, it eventually housed an Aim Controls EQ2 German Mount - It just fitted, though not with any equipment in place.

I had some problems with rainwater running under the shed from behind. I sorted this by giving the deck a slight front to back tilt. I added the shelf into the floor of the shed to store the 12V power supply and dew shield. Out of shot is a thermostatic frost heater (B&Q 500W) which runs at its lowest setting throughout the winter.

With the shed rolled forwards the scope is well protected and the overall impression is not too intrusive. It certainly doesn't look much like an observatory.

I added a hook to hold the door back when the shed is being rolled back. There are also a couple of galvanized handles at the rear of the shed to make pulling it back easier.

I used some spare roofing felt to act as draught excluder at each side of the door and at the sides of the shed. In use the shed keeps doesn't hold the damp, even though I do get a little dew and rainwater running along the groves in the decking boards. I this becomes a problem I will probably jack up the South end of the deck to make the water run away from the shed.

Power is supplied to the shed from the RCD protected socket you can see on the wall of the garage.

The hasp and padlock provide basic security and also help improve the structure's rigidity.

Borg 100ED F/4

The Borg range of scopes are made by Tomy in Japan, but they are certainly not toys! It can be quite confusing when buying a Borg as they need to be configured to suit your needs. You can end up wading through on-line catalogues working out what you need. the optical quality of the ED lenses is is excellent, should next to no colour when in focus. I have in the past owned the 76ED, which I loved. I never thought I'd part with it as it met all my needs for a short focal length refractor, but about a year ago I got the chance to buy a Borg 100ED F/4. This is the 115mm tube variant with built in field flattener/reducer capable of use with Pentax 67 cameras. I thought this would make a great partner for my Yankee Robotics Trifid 2 6303 imager. I was not wrong. Optical quality is excellent and the cell is even collimatable. It breaks down into small component making it suitable for airline travel. It is more versatile than my 76ED, but I still miss the latter.

The optical configuration is shown here

Friday, 27 April 2007

M106 Widefield

Monday, 23 April 2007

The Integrated Flux Nebula near M81

These are a thought to be dust clouds high above the Milky Way that are illuminated by the light from the galaxy core. As a whole they make up the largest reflection nebula in the Milky Way.
The inverted image shows nebulosity better. This area has been coined the Volcano Nebula.
This was taken under excellent condition for the UK, but it really needs more exposure under even clearer conditions. New Mexico would be better.

The Coma Cluster, Abell 1656

One of the densest galaxy clusters visble from the Northern Hemisphere.

Image Details:
L=20x240s Binned 2x2
RGB=4x120s Binned 2x2
I used the Vixen VC200L at f/9 1800mm FL and the Trifid 2 6303 CCD imager.

NGC3628 in Leo

I don't know how messier missed this one in his classification of major nebulae as its certainly the star attraction of the Leo Trio.

I recently acquired a s/h VC200L (high res/aperture withdrawl Roll Eyes) After a bit of a trial getting it collimated - these are really picky beggars, I got a chance to use it in anger last night. This image was auto-guided through a 200mm telephoto lens, and I need to sort out the flexure as there is some trailing.


VC200L at f/9
Trifid 2 6303 L=17x240s binned 1x1, R,G&B=7x120s binned 2x2

I'm really impressed with how flat the field is with this chip, but the vignetting is quite severe, so I'll need to take proper flats for future images.

Tuesday, 17 April 2007

The Seagull Nebula in H-Alpha

Here's my latest image from the deep south (of Orion). I used the Baader 7 nm filter to cut through the light pollution.