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Cassiopeia Double night


MattJenko

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After a disappointing holiday in Devon from a clear skies point of view (great time otherwise), I returned to Essex last night to be greeted by a few stars in the sky. The view in Devon was North facing, different from my south facing garden, so I took my Dob out the front with its security lights and road junction and went hunting for the objects I had lined up for my holiday. This was to be a Cassiopeia night.

Iota Cas. Found this after a bit of a struggle to even see the fainter end of the W! Once found however, this turned out to be a great test of my eyepiece set. Firstly, all 3 were just visible in the TV Radian 10mm. I tried a 2.25 barlow, but as usual, I struggle with barlows, maybe as I have a single speed focuser, maybe just because I struggle. I also compared the view to the Skywatcher 10mm that came with the scope and happily found the view not as crisp as well as narrower and darker, although still splittable. The barlow was pretty much unusable in this eyepiece.

The Baader Zoom was tried, as I have not had a huge amount of joy with this EP in this scope. This was a happier experiment. The zoom is very useful at finding and then splitting and the 8mm full power (which is actually my highest power at the moment) also made the 3 way split quite easily. The barlow again was a bit of a blurry mess. I need to get some proper high power eyepieces it seems as the barlow approach simply is not working for me. Radian 10mm for the rest of the night.

Another thing I noticed is that I am having balance difficulties with the Dob and think I need some counterweight to help prevent the forward tipping and the extreme tension required to prevent slipping.

Next up was Struve 163 (can you tell where this list comes from!). I had already seen the triangle in my hunt for Iota Cas, so this one was pretty easy. What great colours! The C star was far enough away that it didn't even seem like part of the group. This is a mag 10.7 star, so nice to see how I can push the 10''.

Eta Cas was a nice sight and quite easy to find and it was good to gauge how 13 arc seconds looks like in a 10mm EP. However, I could not find the next one, Burnham 1. Even with a clear guide, I just couldn't make it out and will leave to a night when I have more power and possibly darker skies.

Struve 3053 needed a couple of restarts back to the starting star to get, doing the run from Gamma to Kappa and beyond. What a nice reward though. A littler Albireo, with a lovely and crisp orange and blue combination. From the spacing earlier, this looked a little larger than Eta Cas, and so it proves as this is a 15 arc sec difference, so getting a feel for this. To bring me back to earth, Sigma Cas completely eluded me after, and as the clouds started to roll in, I used my MaxVision 28mm to get a feel for stepping with this low power EP and judging distances between the main Cassiopeia stars (2.5 EP width for the Alpha->Gamma step by the way!).

All in all, a very enjoyable hour or so and great to get some time and experience at the eypiece. I used a chair this time rather than a kneeling mat, and preferred it I think, although doing finder work with a straight through is a neck-cricker...

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Nice stuff Matt :smiley:

Iota Cass is one of my favourite multiple star systems. It can be challenging with my 4" refractor though as the closer star sits right on the diffraction ring of it's brighter companion.

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Lovely report and thank you for sharing :smiley: I agree that double stars are some of the most attractive sights in the night sky and so it's great to see a little list and your own insights into these cosmic gems. I have read a few guys here doing their own mods to balance their dob-newt set-up. I'm not sure if it helps but these links might give an idea to work on: dob magnets, Adey's post.

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Great report. I've got the 8" skyliner but same ep's. So decided to try to follow your adventure. Only managed lota cas and eta cas before the clouds came in, but these are my first doubles.

Are you using the baader Barlow? I have issues with the drawn length on the standard focuser when using the Barlow.

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I did try the zoom with the barlow. My scope has a 2'' tube extension in the drawtube which is where I put the zoom without the barlow, using the zoom 2'' adaptor. This requires the tube to be almost all the way in. When using the barlow, I swap out the whole 2'' extension and put in a 2-1.25 adaptor on the drawtube which has a little extension, but not much and again this just gets focus at almost fully in. It doesn't get to focus when  not using the extension. If you want I'll take some pics to show when next out.

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