Skywatcher Skyliner 250px 10-inch Dob First Light

[eifionglyn]

Although I had a quick look on delivery day, I don't count a quick peek at full moon a "proper" first light for a ten inch Dob. Tonight however, the forecast was clear, the moon not due to rise till about 9pm and my garden fence probably buying me an hour after that, the big Dob was duly carried out to the garden, plonked in its mount, and... ...well that's about it. Refreshingly quick and easy to set up compared to my previous 200p / EQ5. Allowed it to cool while supper was eaten, then out with star atlas and red torch in hand.

All my observations will be comparisons to the 200p I had previously. First up M31. Easy to find as I know where it is, but I'd not really got the hang of star hopping yet. I'd cut a 5-degree hole out of a piece of black card to use with my charts to simulate the view in the 9x50 finder, and actually managed to star hop properly to M31. I think this was due to having a RACI finder, so much easier when you can just glance quickly from the chart to the eyepiece without performing the back breaking yoga moves needed with a straight through finder. It's a necessity on a Dob I think. however, you can't do the trick that works with a straight through finder of looking through it with both eyes open to line up the crosshairs with a naked eye visible star. I've fitted a Rigel quick sight to the Dob as well, it's a great combination with the 9x50 RACI.

Anyway M31 is big. Filling the field in my 18mm eyepiece, I could see a definite brighter region in the core compared to the edge, not noticed that before in the 200p. I also saw for the first time M110. I'd seen it in images and on the charts of course, but never spotted it myself in the 200p and had assumed it was a photographic only object, but no there it was, actually quite clearly visible and separate from M31. Very happy.

So, I decided to test my star hopping with something I'd not seen before, M33. Returning to Mirach I slowly worked my way south and east, constantly comparing what was on my chart to what I was seeing in the finder. Soon I had the finder crosshairs on where M33 should be. Looking through the eyepiece and - nothing there. Hmm, went to have a little scan round with the eyepiece and as soon as I moved the scope it popped into view. The movement was just enough to make the very faint galaxy reveal itself from the background. This was fairly low in the east as I was observing, the sky already lightening due to the soon to be rising gibbous moon. I will revisit this at new moon to compare. Very happy to have seen it at all.

Next was the double cluster. Wow. Utterly breathtaking in the 10 inch Dob. Rich, detailed, colour differences between individual stars apparent. 

Las of all I turned west to say goodbye to Lyra, my favorite summer constellation and focussed on M57. The familiar smokey grey ring appeared, but bigger, brighter and more contrasty that in the 200p. In the 200p it looks like a planetary nebula which you can convince yourself has a ring shape in fleeting moments of clear seeing. In the 10 inch, it's absolutely positively a slightly oval shaped ring, no doubt about it. It also stands out much better from the background than I've seen before. The 18mm BST plus a 2x Barlow was probably about the sweet spot for this.

All in all I'm very pleased having switched from an 8 inch on an EQ mount to a 10 inch Dob. I don't miss the RA tracking at all, found it very easy to keep up with objects just nudging the scope, and because the mount is that much more stable, the views between nudges are that much better. I wasn't expecting that much difference between the 8 and 10 inch but it really is quite noticable. Anyone undecided between the two I can heartily recommend the 10. It's not significantly heavier that the 8, and the extra aperture is worth it IMHO. Just budget for a RACI, a red dot / Rigel / Telrad, oh and a chair. Being able to sit, comfortably with your eye at the eyepiece is incredibly enhancing. I'm now a fully paid up member of the Dob Mob!

[John]

Nice report - thanks very much for posting it 

10" of aperture can really give some great views of deep sky objects.

You probably saw M32 as well as M31 and M110. M32 is a small fuzzy spot close to M31 but on the other side of it to the much fainter M110.

Well done for picking up M33 too. It can be an elusive target when there is any light pollution about and it's easy to overlook when you have not seen it before.

[AlexB67]

Glad you like it, it is indeed a fine instrument if I may say so myself. I had it out earlier and really after while it is so manageable,  and it packs a punch without breaking your back     M33, not sure why it is so elusive, well I can appreciate it, but I've seem it in the 5 inch numerous times from my backyard wen it is high up in the sky on good nights and all the city lights  go off in  lot of the neighbouring area too. I am sure of it, and once I got the 10 inch only nailed that I was looking at the right thing all along. On a better site I saw it in the 5 inch more clearly. In the 5 inch there is just nothing there except for a very subtle lighting change in the background in my garden, but the star hop and location is easy to get to where it is, so I know when some evenings it is there and when it is not.

With all that rain and stuff I hope to pull the 10 inch under a darker sky and hopefully see M33 in better detail, I can't wait for that but that weather has been awful lately so it hasn't even happened .. yet.

[cybernautic]

Sounds like a good view of M31 was had. I'm surprised you couldn't see M110 in an 8'' scope though as I saw it very clearly last night in mine.

[swamp thing]

Nice report. 10" Dob, tough act to beat

A 10" Dob does show the double cluster marvellously well doesn't it?

Next time on M33 try going back to the finder, and tap the scope. You'll see it in there too.

[estwing]

nice report....like steve says 10" dobs are great...and 12" ones, 16" are good 18" one aren't too bad 8" are super portable 20" are ok I suppose  oh and welcome to dobsville!

[Astro Imp]

Nice report, pleased to read you managed M33 a real tricky little blighter when there is any sky glow around.

As others have said I'm surprised you didn't manage M110 in your 8" as I have had good views from my moderately light polluted garden on good transparent nights in my 6".

I was especially interested to read your comparisons with the 8" as recently I have been trying to decide between the two if/when I upgrade.

Thanks for posting and good luck for the future with your new toy.

[A McEwan]

Very nice! I have a new 10" Dob too but no first light yet. I'm looking forward to testing it at my dark sky site soon...

Ant

[eifionglyn]

No, for some reason I'd never managed to spot M110 in the 8 inch, which surprised me also, but there you are, I'd spent long enough viewing M31 in the 8", but never saw M110. It was so clear in the 10 that my first reaction was "what the hell is that?" took a little bit of head scratching and looking at the charts followed by an image search online to confirm it was M110. Perhaps the 8 was only showing me the bright core of M31, so M110 would have been further away than I was expecting, so maybe I never actually looked in the right place.

As for comparisons with the 8 / 10 in terms of living with them, the 10 inch tube not noticeably heavier to move, and the base is certainly easier than a tripod with an EQ5 on top. The tube isn't any longer either, though of course it is wider, but doesn't take that much more room to store. If you've got the money to buy it, I can't think of a reason not to get the 10.