Success finally with the 12" dob

[drummerp]

Last night was a lovely clear evening. Firstly we had to sort out the problems of blurred images we were getting.

I purchased a Lazer collimation eyepiece and this definately did the job.

We had great views of the moon before it went below view. We had never seen the moon with a 12" scope before and even with a 36mm eyepiece it was so defined, clear and crisp it blew my socks off.

We then focused on Saturn yet again for a short while and the image was lovely, the rings were clear and we could make out 3 or 4 of its moons the scope showed no signs of blurry image although, the real test was going to see what the M13 looked like.

So then after about 5 mins of looking we found it, The M13, light pollution was still quite high from the moon going down and the neighbours back window lights as we were at my parents house but, we changed to a 20mm plossl eyepiece and took a while to focus and the image was amazing. Only once before had we seen the M13 so clear and full of life and that was at SGL4 with Johns Ethos so for us to see it and be able to keep looking at it for quite a while taking in its detail was great. Collimating your scope definately works and we will now be doing this simple 2 min exercise before every viewing session.

Finally, we tried looking for the M3 now we did eventually find it and again the cluster looking just just as detailed as the M13 but we also saw somthing else that we are unsure of, it may or may not have been a large galaxy which was to about 1 arc min above and 1 arc min to the right of Acrtusus but it had what lookedl ike a central star with a very thin bright line going straight through it. At first we thought it was a bit of light pollution that could have come from Arcturus seeing its soo bright but we looked on Stellearium and their are a couple of galaxies in the area so it might well have been anyway, I've drew this quick image of what we saw for. was it a galaxy or just some stray light ??

Cheers

Neil

[Doc]

Well done on finding M13 and M3.

Looking at your photo it just seems like a meteroite you saw. I see loads of them while observing. They appear as a short streak of light you then look away from your scope to see if you can see it unaided and of course you can't as it's way to dim.

[drummerp]

Hi Mick,

Thats not a photo, its just a drawing I did in paint shop to show what we saw. We were looking at it for about 20 mins and. It wasn't no meteroite, we've saw plently of them in the past.

Cheers

Neil

[Doc]

I don't know what it was then as I've never seen anything like that through my scope and I've been observing quite a few years.

I also cannot believe it's stray llight if you observed it for 20 minutes.

There are a couple of gallaxies close by but they have a surface brightness of mag 13.2 so are going to be very dim unless you are at a really dark site.

I don't know I stumped

[brianb]

saw somthing else that we are unsure of, it may or may not have been a large galaxy which was to about 1 arc min above and 1 arc min to the right of Acrtusus but it had what lookedl ike a central star with a very thin bright line going straight through it.

Ghost images of Arcturus caused by reflections in the eyepiece ... almost certainly.

[Astro_Baby]

Might have been a tube current. When looking at bright objects with the 8" ( Polaris for instance ) sometimes the scope produces a long streak shape similar to that when its not reached thermal equalibrium.

I used to worry that its some disastrous fault with the mirror but it goes away after about 2 hours and I know thermals can produce strange results.

[Talitha]

Thanks Neil, great report (hope you found your socks, lol).

[drummerp]

Thanks, cheers guyds and girls, I also didn't think that it was anything like a galaxy we were seeing, "Tube currents" or "Ghost images" seam more plausible.

And my sock are ok now. lol

Cheers

Neil

[albedo0.39]

Good report Neil and I look forward to more reports from the big Dob. Looking @ your image and it being late at night, I think it was an Interceptor launching from Shado Moonbase to strike at a UFO.

(Oh alright... I have no idea either)

[John]

Great report Neil - I'm really pleased that you have the collimation sorted now so the scope can unleash it's potential !.

I can't shed any light on your mystery object though I'm afraid

A 12" scope really does well on globular clusters I've found with many of them being capable of resoloution into stars. Try M92 in Hercules as well - it's tighter and a bit smaller than M13 but a very impressive sight in a 12" scope

John

[M110]

Nice report Neil - glad you're 'getting on' with the 12" (Claire has let you use it then! )

I've found M5 in Serpens is another great cluster - the world really is your oyster with this size scope!

regards,

Alex

[SimonC]

Nice report Neil,the Skywatcher Dob must be a cracking big scope!

[acey]

Congratulations - I'm sure you'll have a lot of fun with the 12-inch.

Regarding the mystery object, I agree that ghosting or some other form of light scattering is most likely. You mention the issue of nearby light sources (e.g. from windows) and these can throw up big streaks and flashes. If everything is stationary then the streak will stay there for as long as you look.

If you don't have a dewshield, I suggest you add one (made from a camping mat). I use one on my 12-inch and as long as the shield is dark on the inside it will help cut stray light (if it's bright then it might actually make things worse). Also try to avoid direct light shining on the eyepiece - you could try covering your head with a hood, or shielding the eyepiece in some other way.

I'm assuming you have the solid tube rather than flextube but if it's the latter (which I have) then it really has to be shrouded when used in a light-polluted environment.

Some eyepieces are more prone to internal reflections than others, so that's another consideration.

But it sounds like it didn't mar your viewing too much, so it's not a biggie to worry about. Just not something to spend twenty minutes on when you could be enjoying DSOs instead!

[drummerp]

Thanks Acey and everyone else.

I haven't been able to use the scope's much since then.

The 12" is a Flextube and I am in the process of having my Mother make us a Shroud for the scope and I'm also looking to purchase a dewshield or as you mentioned, a "camping mat"

A Light pollution filter is also something I'm looking to purchase soon.

Cheers

Neil