John

You could try a "wanted" advert in the UK Astro Buy & Sell website on on our classifieds section. You never know what might be out there !

Well done Mark

When you star tested, were you getting a reasonably well defined airy disk and diffraction ring / rings when at sharp focus ?

Or as the star image quite "hairy" ?

I have observed with an 8 inch SCT that was struggling to split Epsilon Lyrae (the "double double") a while back but that did turn out to be out of collimation when we star tested it.

Two things spring to my mind reading your post: cooling and collimation. If you got the scope out at 16:00 hrs then I assume that it had cooled for a decent time before you observed ?

Did you star test to check the collimation and, if so, how did the star test look ?

The intra and extra images of a star such as Polaris show much about the state of cooling and collimation of a scope. Plus, it's another double star of course !

Your 8 inch SCT should be resolving the double stars you mention, some pretty easily. Mars is whisking away from us now and it's disk is now less than 9 arc seconds but should still be visible as a disk with vague dark markings just about visible. Uranus should show as a grey-green disk, although small, but plainly a disk, at around 200x magnification.

I expect you have seen this web page ?:

http://www.astrophoto.fr/collim.html

I use the Skytee II which is effectively the same as the TS AZ5.

It handles both my 100mm F/9 and 120mm F/7.5 refractors quite easily without the need for a counterweight.

33 minutes ago, Jiggy 67 said:

I can never get my head around these comparisons to the moon.......are these representations as they would be naked eye??......

No, telescope or binocular views I think with the moon is projected onto the target object to show the scale of in relative terms.

They say that, to the naked eye, the moons disk is about half the size of the nail on your little finger, with your arm outstreched:

So I guess that two fingers would cover about the total size of the Veil Nebula complex, as seen with the naked eye (assuming that you could !) ?

7 minutes ago, SiriusB said:

Any chance you could expand on this please for the benefit of all?

I'd been given  to believe the best(bandwidth) nebula filters work best with larger scopes due to light loss? If you've only a small scope......

Thanks.

I used to think that but I have found both UHC and O-III filters effective with apertures from 80mm and upwards.

I used to stick with the "generous" (bandwidth) Baader UHC-S filter with smaller scopes but having tried more regular UHC's and more recently O-III's with such scopes I find them more effective despite the smaller light grasp of the scope.

Hopefully Don will see this and explain some more.

From the same source, some graphical representations with the moon for scale:

https://calgary.rasc.ca/bigthings.htm#Images

Short and sweet, not to mention noisy !

I guess they will be poring over all the data they got now.

I wonder what the local wildlife makes of it ?

I thought I might be in luck tonight as well but the "sucker gaps" in the clouds have progressivly got smaller and smaller so the sucker has given up now and bought the scope back in

I got some views of Rigel, Alnitak, Zeta Orionis, Beta Mon in a few favourable cloud gaps but the seeing was rather mediocre so chasing around the sky not that rewarding. 32 Orionis was just about split and 52 elongated. Nothing really at it's best though.

Sometimes you just have to beat a retreat !

I came across this list on another forum and thought it might be of interest / use. It is maintained by the RASC Calgary Centre and has information on targets that are as large or larger than the moon in apparent angular size (ie: larger than half a degree). Might be useful in planning observing / imaging ?. Covers N & S hemispheres:

https://calgary.rasc.ca/bigthings.htm#Table

The biggest couple of targets size is expressed in degrees, the rest in arc minutes.

Big test of Artemis SLS rocket engine due within the hour. Live streaming here:

https://www.nasa.gov/multimedia/nasatv/#public

The Sky-90 was a rather unusual scope for Takahashi and there was a fair bit of controversy around it's optical characteristics, maintenance of collimation and handling of CA. From the reading I've done on that model (I have not owned or used one) I suspect much of this was down to misunderstandings though.

Roger Vine's review is interesting:

http://scopeviews.co.uk/TakSky90.htm

20 minutes ago, Peter Drew said:

The 120ED would be even better.  I have two 80mm ED's, a 102mm Flourite, a 127 triplet and a 150 mm SWED.  The 150 is my preferred planetary refractor.    🙂   

The ED150 would put the AZ-4 under a bit of a strain though ......

4 hours ago, Jiggy 67 said:

I had a good look at TA a few nights ago, lovely double but found it to be a really tight split, how did it look through the Tak?

Quite a clear split at 225x. It's a 4 arc second gap but quite a large brightness difference between the components - mag 2.6 and mag 7.2, which makes it more of a challenge. The dimmer star can be hard to see if the seeing is wobbly or if the optical system is throwing up some diffraction.

A lot of these scopes are made by the same manufacturer.

The Stellamyra is made by Long Perng. I think the TS ones and maybe the Altairs are Kunming United Optics ?

Great to watch - thanks Jeremy

So good to see skill, care and pride combining with quality materials and design to produce an exceptional product

I feel lucky to own one.

These people in the UK sell Istar achromatic objective lenses:

https://www.peak2valleyinstruments.co.uk/page_2238911.html

Just now, Carl Au said:

Oh dear, I am more confused than ever now. I know AstroPaul. If he is same bloke I am thinking about. Not seen since a lecture at the University of Hull a few years back. 

Will this be the only scope you have ?

Personally I would go for a 2 inch diagonal then you have the option of 2 inch eyepieces / filters etc, if and when you want to move that way.

The views of big DSO's such as the Veil Nebula and M31 with my 102mm F/6.5 Vixen and 2 inch eyepieces are some of the highlights of observing for me. Then you can bung in a really short FL eyepiece and get 200x plus on the moon, planets, double stars. Versatility 

Nice report Nik !

Unfortunately I had lost the clear sky before Orion hove into view here. You are right though, that magnificent constellation is packed full of delights. You can easily spend a whole session there 

When you get some steady observing conditions try 32 Orionis with your big Mac and then to really push things, 52 Orionis on the other side of the constellation closer to Betelgeuse. You 180 should be able to do both under good conditions. 52 is around a 1 arc second split so very seeing dependent.

Hate to be different but sub-100mm scopes have never really satisfied me. I've owned a number of good quality 70mm, 80mm and 90mm refractors but for me the smallest aperture that I find provides lasting interest is 100mm.

I'm sure the Stellamyra 80mm is a superb example of that aperture though. 

I've owned a Vixen ED102mm F/6.5 for many years now and found it an excellent and versatile scope so faced with the choice you give, the 102mm F/7 would be what I would go for.

It would be a strange world if we all agreed wouldn't it 

37 minutes ago, Mark at Beaufort said:

.... Getting very frustrated with constant cloud cover.

Me too Mark. Cloudy here again now

3 minutes ago, Captain Magenta said:

Whenever I search out Uranus I can definitely recognize it for its bluish hue, but then at mag 5.something compressed into a small area perhaps that would be expected? Neptune too

Yes, I agree that colour tints are easier to see in a more condensed target.

Uranus looked distinctly green / grey disk when I observed it just now. That was with a 100mm refractor at 300x.

When I used my UHC filter on Messier 42 with the 12 inch dob a week or so ago I thought that the green tint was enhanced around the "fishes mouth" area and possibly even very subtle pink added here and there to the "wings" but I'm a little wary of what I think I'm seeing, colour-wise, with a filter in place