January 2021

Birthday Clear Skies

  • Nik 

Monday was my birthday and as a present the skies cleared.

Only drawback was that we were due to go round to the daughter’s house for tea and cake. (She lives alone and we’re in a support bubble with her so this is OK under COVID-19 regulations). Luckily I have a VPN and I talk to my observatory computer using Remote Desktop so as long as I can get away with taking a laptop with me I’m sorted.

Monday the moon was in Gemini and near full. The seeing wasn’t predicted to be great but there was little cloud cover forecast.

My setup was more or less working with the exception of the dew heater and focuser. Since these use the same board I suspect it’s a power issue but it was too late to fix them.

I decided to risk it without dew heaters and given the temperature I’m amazed I didn’t get ice forming on the lenses.

I was using my Explore Scientific ED80APO and my 183C Hypercam with PHD2 guiding.

I managed to capture about 2 1/2 hours of light on M42. A combination of 5 minute, 2 minute and 1 minute subs. I’m quite pleased with the result.

ES ED80APO, HEQ5 - Guided. 10x300s, 28x120s, 18x60s. Total exp. 2hr6mins
ES ED80APO, HEQ5 - Guided. 10x300s, 28x120s, 18x60s. Total exp. 2hr6mins

Astroshed Update

  • Nik 

So after much heaving and very precise setting up with the new tube extension the scope fits and clears the sides. It’s definitely touch and go though, I’m having to park the scope in a weird position and remove the counterweights before I put the roof on.

Basically could defo have done with a 6×6 shed. Shame I didn’t have room.

I’ve also cut the top strut and am now using this to close the gap between the two roof panels. The shed may have survived storm Christopher but the roofing felt didn’t.

Might even be a bit of clear sky tonight so fingers crossed for a test run.

January Blues

  • Nik 

So January, what can you say? Orion in the sky, fabulous targets to image, nice long nights.

On the other hand here in Cambridge, wet cloudy skies all month, locked inside (which I fully support by the way), no chance of pointing my scopes at the sky. 🙁

Fortunately this doesn’t mean I’ve got nothing to do.

Computer upgrade

Firstly, I’ve replaced my ageing, slow observatory computer with something a bit more modern (an Intel NUC). Fairly cheap and the RAM and SSD from the old one (A 4 year old dual core GigaByte Brix) swapped right over which keep the cost down a bit.

I managed to try this out just at the end of December and it seemed to work well.

NGC 7635
NGC 7635 - Skywatcher 200PDS + Hypercam 183C Pro + CLS. 31 x 300s exp. Total exp 1h5m

New Observatory Shed

Top of my wish-list from November was a new shed to house my kit.

I decided I didn’t have room in my garden for a 6×6 shed so after some careful calculation I decided to buy a 6×4 because my rig should fit.

My careful reasoning when thus:

  • Base of tripod forms an equilateral  triangle 47″ on a side.
  • That gives an inradius of about 20″ (which is the largest circle that can be contained in the triangle). So if the sweep of the tube rotating on the mount sits within the inradius then all should be good.
  • My biggest scope is under 40″ in length and balances roughly in the middle so should fit within the inradius
  • The smallest dimension of the shed is 48″ so that should leave 4 inch either side of the inradius.

So given the above reasoning I should be able to get away with a 6×4 shed.

I went for a Keter Darwin 6×4 because it was fairly economical as sheds go and plastic. Looking through the manual online it looked like it should be fairly easy to modify the roof to lift off and it was.

Basically I built the shed according to the instructions until I came to assembling the roof. The roof consists of two plastic panels and a top strut which runs along the top and the provides an overhand to the panels to make them water tight.

Rather than screw the panels to the shed I’ve fixed the panels to the shed using 8 hasp locks and I’ve replaced the top strut with a flap of roof felt on one of the panels which folds over the gap at the top. (I may try and reuse the strut at some point but this will do for now).

So far so good, from this point on the fun begins. Turns out that my assumptions about the HEQ5 tripod weren’t correct.

The mount doesn’t centre over the centre of the triangle but is more towards the back two legs (I guess this is so the back two legs of the tripod brace the load). So the sweep of the telescope tube moves backwards towards one wall by more that the 4″ margin I have.

The upshot of this is that the tube hits the walls a various angles.

Luckily there is a solution to this, raise the mount up and move the tripod towards the other wall.

So I’ve brought a load of cocreate blocks and used them to make a base for the tripod.

This raises the mount up high enough so that it sits in the roof (just) and doesn’t hit the walls.

I’ve just ordered an extension tube for the tripod so it’ll be easier to centre the tripod in the shed, and as an added bonus I won’t have to worry about the end of the tube hitting the tripod legs 🙂