Finally some clear skies!

  • Nik 

Finally the weather has changed and there are a few resonable nights ahead to start my summer project.

Last night was a bit truncated with cloud starting to come in around 2am but I at least go my rig setup and working nicely

This month’s target is NGC 6960, the Witch’s Broom nebula. The plan is to leave the rig setup for at least the next four days and (hopefully) start imaging as soon as it’s dark enough.

The plan is to capture NGC 6960 as a two frame mosaic, but with the top half framed nicely so if all else fails I’ll have a nice shot anyway (since my previous attempts at mosaics has been less than stellar). To test the setup last night I managed to get around 1 hour with of goodish data, so 30 minutes pre integrated frame (nowhere near enough data).

Strictched and stretched only

The new garden

The new garden is a lot smaller that the last one and has two trees in it. I’m still in the getting to know you phase of working out where is best in the garden for certain shots and I think I’m going to be moving the scope about a lot more to take specific shot of targets that at our previous house. On the plus side the garden is further away from the street lights 🙂

Given that the south is more obscured that the last garden I’ve been thinking of running two scopes per target too get extra data/time on targets whilst they are visible but of course that comes with quite a cost.


  • Nik 

Well I was hopeful tonight that the clouds would part and I’d finally be able to try out my scope in the new garden. I have to say that I did see some stars very briefly at around 10 pm before it got properly dark but not for long enough to polar align my scope, let alone do any useful imaging. Now has downgraded their forecast to basically cloudy all night instead of clearing at around midnight.

About the only interesting picture I've taken tonight

So everything back in the house until the next clear night (sometime next year it feels like :-s )

Clear skies and no telescope

  • Nik 

The house move is (more or less complete) or to put it another way our new house is full of boxes.

I was sorely tempted to try and setup my rig in the back garden on Friday night (the day we finished moving) but sanity prevailed.

Tonight doesn’t look to bad so I think I’ll give it a go.


  • Nik 

A nice clear, dark, moonless (well until about 4-30am) night last night. Came as bit of a surprise since I hadn’t been keeping an eye on the weather recently since we’ve been packing.

Setup seemed to go well, which in my experince is a sure sign that something else will go wrong later on. Sure enough I couldn’t get my guiding working decently, so I ended up being limited to 3 minute exposures.

I really wanted to have one last go at the cone nebular but it was far to low in the sky by the time I got everything working so I settled for M101. Seems to have come out quite well.

200PDS + Hypercam + HEQ5. 300s x 14, 180s x 60, approx 4 hrs total exposure

Rosette Nebula

  • Nik 

Way back on the 3rd February I had a go at imaging the Rosette Nebula and I’ve finally gotten round to processing the data.

ES ED80APO, HEQ5 - Guided. 600s x 12 / 300s x 12 / 60s x 19 subs. Total exp. 3 1/3 hrs

29/30/31st March 2021

  • Nik 

So three(ish) nights of fairly clear skies with fairly good seeing finally. Pity the moon was waxing but we can’t have everything.

So I had quite a loot of light for this shot of M81 and M82. Some of it was fairly light polluted though and there was some high cloud in some but I though I’d see what I could make of it by just dumping the whole lot into Astro Pixel Processor. I think it’s done a reasonable job but I did initially end up with a fairly blotchy background.
Skywatcher 200PDS, HEQ5 - Guided. 600x 42 / 300 x 50 / 180 x 20 subs. Total exp. 12 2/3 hrs

I used the APP light pollution tool on the complete stack and then used PixInsight to stretch and process it. My workflow looked something like:

  1. MultiscaleLinearTransform to do some noise reduction
  2. Stretch
  3. MultiscaleMeridianTransform to reduce the blotchy background
  4. HistogramTransform to reset the blackpoint
  5. HDRMultiscaleTransform to bring out some detail

I had quite a lot of trouble with step 5. The enhancement worked fine in the preview but went wired for the whole frame. In the end I made two previews of the galaxies, did the transform, saved both the images then merged them into the final image using GIMP.

Skywatcher 200PDS, HEQ5 - Guided. 600x 34 / 300 x 34 / 180 x 20 subs. Total exp. 9 1/2 hrs (Selected data)

I’m quite pleased with the first result but I was a bit bugged by the blotchy background so I went through the raw data by hand and filtered out the cloud polluted frames. This cut out about 3 hrs of light.

The background did indeed come out a lot better so step 3 wasn’t needed and step 5 worked on the whole frame but on the whole I like the first attempt better.

Beginning of the Year Blues

  • Nik 

Predictability there hasn’t been a lot of clear sky lately. I managed to get a bit of clear sky in February and a bit more this month but nothing spectacular. I’m a bit behind in processing my images but will post when I’ve finished.

Three bits of news:

Thing one: To fill in the cloudy nights I’ve taught myself basic PCB board layout and got two boards made for my heater controller and sensors. One day I may publish the results but I have to get clearance from my employers before I can do that. I’m pretty sure that over the years it would have been cheaper for me to buy some off the shelf focusers, dew heater controller, etc. but where’s the fun in that!

Thing two: I’ve been trying out AstroPixelProcessor for stacking and am majorly impressed. I now can’t quite decide if I want to fork out £60 quid a year for a subscription (and get updates) or pay the full price. Either way it seems to work well enough for me to squander some money 🙂

Thing three: I’m moving house on the 15th April so tonight may be the last time I use my rig in Cottenham. We’re only moving up the road (from Bortle 4 to Bootle 5 unfortunately) but on the upside the back garden is further away from the road and doesn’t have street lights at scope level wherever I look. There’s a nice flat area right at the bottom of the garden waiting to receive my astro shed, I’m just hoping it won’t be to much hassle to take apart and move.

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 🙂