This month’s composition is a little different from the form I normally follow.  I wanted to get a nice bright single star image, but I also wanted something else of interest in the field of view apart from other stars.  So I took a good look at the star map to see if there was a main star with something nice and interesting lying close by.  I came up with Phecda in Ursa Major for the bright star, and lying close by are the spiral galaxies M109, NGC3953, and a bunch of other galaxies too.  This image was taken with the Sky 90/M25C combo piggy-backed on the C11 in the south dome.  For this image I used 10-minute subs as I wanted a decent exposure for the little galaxy (and to stand a chance of seeing all the other faint fuzzies in the region).  My notes tell me that I managed to get 27 sub-exposures in all and managed to use the lot giving me a 4 and a half hour total exposure time.  It came out well enough, but of course it would have benefitted from even more time – I usually try for 8 hours if possible using the Sky 90/M25C and 10-minute subs meaning somewhere around 50 subs in total.  This is pretty much the “sweet-spot” for imaging from my moderately light-polluted location with the Sky 90/M25C.  More subs will give a smoother image but beyond 50 and you are definitely entering the realm of diminishing returns where it takes a LOT more extra subs to make any noticeable difference.

The clocks have gone back, and if only the Gods would give us some clear decent skies we could be out imaging by 6:00 p.m.  Weather hasn’t been kind to us for a couple of weeks and as we are now getting into winter constellation time I am wishing for a change for the better in our weather.  The mini-WASP is built and ready to go so it isn’t as if I’ve just bought a load of new kit for the weather to mis-behave in this way.  Here’s hoping we have some improvement during this November so that I have something interesting to report next month.

So until December – clear dark skies, and start grabbing those winter gems

The white Aluminium box with 4 x HDD bays is my new “Icy Dock” attached storage unit for the mini-WASP data.  Each evening’s imaging (if we ever see a clear sky again) will generate a lot of data from the 2 x M26C one-shot colour cameras, and I will store all this data on the Icy Dock.  Behind the 8Tb Icy Dock unit there are 2 x 2-bay Icy Box units holding a total of 4Tb (4 x 1Tb HDDs), and just to the right of the computer is a USB3 caddy with a 500Gb HDD attached.  With 2 x 500Gb in the actual computer itself this means something like 13.5Tb of storage on the Windows 7 64-bit machine – should do me for a while before I need to start burning data to Blu-Ray

The sleep deprivation over this past week’s worth of clear Moonless nights hit harder than I thought.  I have just found this data from 28th September – and I can’t remember taking it   Well if that isn’t a bonus I don’t know what is.  Ruchbah (dead centre) in the constellation Cassiopeia with the little open cluster M103 off to the upper-left.  And the whole thing of course sitting within a glorious Milky Way background.  Single frame with the mini-WASP and 18 x 5-minute subs.

Last night I took a single frame using the M26C camera and the one collimated Sky 90 refractor to capture the very north of the North America nebula – an area I have not imaged properly before.  Managed to get 9 frames at 1,000 seconds per frame before lack of sleep hit me and I had to retire to bed   Bolted the 3rd frame onto the previous two, and with a bit of cropping this is the result.  Must admit to being very pleased with this one indeed.

We’re now well into some decent long dark evenings

This month’s object is rarely imaged it seems – I am going to look at the open cluster Stock 2 in Perseus this month.

This is a beautiful, colourful open star cluster lying just to the north west of the Perseus Double Cluster – and THAT’S the reason that Stock 2 rarely gets any air-time – it has a far more glamorous imaging neighbour just down the road!  But to not have a go at imaging Stock 2 is to miss a wonderful imaging opportunity, an opportunity of putting together a mosaic that includes both the Stock 2 AND the Double Cluster!  I have all the frames for this one taken and I am waiting for Noel Carboni to put the whole thing together for me – I think it will make a wonderful image.

Still – back to Stock 2 – this is quite a large open cluster and for once the large field of view of the Sky 90/M25C is needed – that it 3.33 x 2.22 degrees covers the region nicely.  As this is an open cluster it’s the usual 3-5 minute subs and 80 – 100 of them for a low noise final image.

If you can pull yourself away from the Double Cluster – Stock 2 is certainly worth a look, and it provides much more interesting colour than the Double Cluster as well!

Until November – clear, dark skies to you all

And here’s the “straight out of Photoshop” version with no added contrast enhancement or saturation courtesy of PaintShopPro.

The very quick “process” I did on the NGC7000 image below was no more than a DPP pass and bolt the two frames together – would have taken less than 10-minutes as I just wanted to see what the image looked like.  I know there’s a bad magenta caste and the bottom half of the image looks like it’s been through a ringer – but I didn’t think that spending more time and doing it “properly” in Photoshop would make much difference – WRONG!!!  I spent around half an hour doing it “properly” using gradient exterminator and some curves and levels and it came out markedly different – much to my surprise.

Another 1-hour image (only 6 x 10-minute subs) from the early hours of this morning.  This is the North America nebula NGC7000 with the Pelican making a cameo appearance on the right.  This time the mount was dithered so not hot pixels – YAY!!!

I’ve had my suspicions for quite a while now, but for some reason after just over 5 years  it has finally jelled in my last two remaining neurons what the problem has been.

From way back when I was imaging with the original Sky 90 (bought from True Technology) piggy-backed on the C11 – I had this bunch of trailing stars in the corner of the field of view.  It looked like polar rotation (or coma) but it wasn’t dependent on the sub-exposure time (even for very short subs) so polar rotation was written off.  I got a reasonable collimation (overall) according to CCDInspector, but there was always this bunch of annoying stars in the corner.  Then I saw Steve Cannistra had a similar problem which was due to flexure in the camera rotator – I did his fix and the problem stars were still there.

Recently I bought another Sky 90 from an Irish astronomer and this went on to the mini-WASP array as one of the two main imaging scopes.  I was able to collimate the M26C to this scope very quickly, and unlike the other scope I didn’t have to really bolt down the adjusters to the metalwork on the M26C to get good collimation.

So after just over 5 years I finally come to the conclusion that the collimation of the Sky 90 itself is way out!!  Luckily this is the model that has the three collimation adjuster screws on the lens cell.  So the offending Sky 90 has now been removed from the mini-WASP framework and is now sitting on its own tripod ready for yours truly to attempt collimating against a star.  Not done this before for a refractor, so I’ll let you know how I get on, and if the problem goes away.

Even though collimation on the second camera wasn’t too good (again) last night, I still took 6 x 10-minute subs of the North America nebula using both cameras and scopes.  I’ll be looking at the data very shortly.

Well here it is – one hour’s worth of data taken with the two M26C cameras on the New Forest Observatory mini-WASP array.  Still lots to be done before it’s properly tuned in – but I’m pretty close now.  As I was finishing this off at 3:00 a.m. this morning I might well be writing a load of rubbish here – but I’ll carry on all the same.  Note this is just 6 x 10-minute subs from each camera – now try and imagine my usual 8-hours plus with the Sky 90.  I’ve left all the hot pixels in the background as I didn’t have the dither function running last night – but I’ll try to have that going on the second outing.  The collimation for camera 1 (the top half of the image) is spot on – the collimation for camera 2 (the bottom half of the image) is off a little and needs to be tweaked just a bit (lousy stars bottom right hand corner).  However – the field of view is as you can see MASSIVE (there’s M29 sitting at the bottom of the frame, check out the FOV on your favourite planetarium program) – and the M26C cameras really seem to be delivering the goods with only a single hour’s worth of data!!  Well done Terry Platt.

As it looks like it might be clear again tonight I’m off to bed for a couple of hours.