lunator

Hi @Jimboscotland, I would just like to add my experience with observing doubles. At present I have 3 scopes. OMC250, Orion Optics 200mm F6 Newt. and an ST80. The OMC250 gives the best resolution but lives in an observatory I wouldn't want to have to drag it around, it is pretty heavy. The Newt was originally on an EQ5 and was portable around the garden but was a little unwieldy. It is now on a dob base so is very easy to move around the garden and set up to avoid obstructions. This scope gives fantastic views and combined with a quality eyepiece like an orthoscopic will provide a true colour view. The ST80 is on a photo tripod. It is very portable, a true grab and go. The colour correction is ok. It does limit the fainter stars in light polluted skies. Each of these scopes has it's place but if I had to choose one it would be the Newt. I have had it since 2005 and will never sell it. It is a great all-rounder. Cheers Ian

Hi Michael, the WDS is accurate for the brighter doubles e.g. Herschel, Strive and South. The later discoveries such as the Jonckheere pairs can be less accurate when it comes to magnitude. I was investigating J252 (if memory serves) and found exactly the same issue. The pair attributed to J252 were faint and quite hard to observe in my 8" scope from London. Brian Mason at Washington confirmed that Jonckheere doubles are much fainter than listed in the WDS. I don't think that they are updated unless the magnitudes are measured and then published in an accepted Journal. For these pairs I add a minimum of 2 magnitudes to the WDS figure. Cheers Ian

Caught one by accident last night. Using my 8" dob at x50 whilst viewing a few doubles in Bootes. It was quite bright fast and white. Cheers Ian

Hi Spile It's a case of fat finger syndrome 😀. It should read STF2954 a pair with 41" separation. Cheers Ian

Cheers Rusted I will have a look at that.

Continuing my lunar imaging journey I had a go at Gassendi. Fairly happy with it. Cheers Ian

Hi Stu The accepted view is that anything below the Raleigh criteria shouldn't have a clear split, the definition of this is a clear black line separating the stars. You can still resolve pairs at the Dawes limit or below. There are several descriptive terms used such as snowmen, figure of eight. I tend to be more boring and just noted if it is not resolved/resolved or split. Cheers Ian

A quick pic of STF333 A close pair but fairly evenly matched. This is a quick process from one avi frame converted to Jpeg. Cheers Ian

Hi Stu Nice investigation In my experience at the resolution ratio of 1 (1.16" for your scope you can see pairs upto 2 magnitude differences. At a resolution ratio of 0.86 (1" in your scope) a delta M of 1,5-1.7 is still possible to see. Conditions have to be right tho' Cheers Ian

Hi Chris it is a tricky one. I am working out what the scope camera combination can deliver. I managed to get STF333 last night. I will post a pic. Cheers Ian

I'm a bit old fashioned The capture was in Sharpcap. The stacking is AS3 and processing is Registax 6. cheers Ian

I have been messing around with the new ZWO ASI178. I chose it for the small pixel size as I have taken images of double before but I am hoping I can push the limits further. I had a quick session last night after a bit of lunar imaging. I have never tried for Theta Auriga but after testing everything on Castor I thought it was worth a try. The set up give me 0.22" per pixel which for deep sky imaging is crazy but by reducin the ROI to 640x480 I could get 60 pps and this allow me to stack in AS3 and crop in GIMP. I am fairly satisfied as a first pass. Hopefully I can get some trickier doubles captured. Cheers Ian

Still getting to grips with the new ASI178 It is an excellent camers but it does make demands of the scope. Clavius looked good last night. I think I might be able to tease out some more detail but still getting the hang of processing

Hi William Some good pics there. Cheers Ian

Danny Good start they are very good images. Cheers Ian

Hi Michael nice report A good mix of targets Cheers Ian

I had a chance to get out for an our on the 21st so had a quick look at a few pegasus doubles. using the OMC250 and the 32mm and baader zoom. STF2818AB Y/B A wide pair with a noticeable difference in magnitude. The primary is yellow-Orange and the secondary blue-grey. Several bright stars in the field. STF2889 Y/B A tight pair with a moderate difference in magnitude. The primary is yellow-orange and the secondary is a blue dot. STF2934 Y/B A tight pair with a moderate difference in magnitude. The primary is yellow. The secondary is a small blue dot. Best view at x140. STF29454 w/w A very wide pair with a slight difference in magnitude. Both stars appear white. A bright star shares the field (HD216698). STF2967 w/b A fairly close pair with a moderate difference in magnitude. The primary is white, the secondary is pale blue. STF2969 w/w A close pair with a samll difference in magnitude. Both stars appears white. Part of a 5 star asterism like a dice pattern. STF2997 w/b A wide pair with a moderate difference in magnitude. The primary is white, the secondary is blue-white. STF3000 w/w A close pair of white stars, fairly evenly matched. Just visible at x70. STF3014 w/b A fairly close pair with a moderate difference in magnitude. The primary is white, the secondary is blue-grey and faint. Cheers Ian

I have never split this but it is one I should try a bit harder with 😉 I have a look through my spreadsheet and the nearest comparable split I have is with STF2900. At the time it was ~0.7" and the delta M was about 3. The pair are much fainter than Dubhe. It took x450 mag to split. So I think Dubhe may take something similar. Cheers Ian

Magnus To give you an idea how difficult Procyon B is have a quick read of this thread https://stargazerslounge.com/topic/374993-one-step-beyond-sirius-procyon/#comment-4065839 Cheers Ian

It is a tough split. I have managed to split it in my 8" Newt and OMC250. It usually took about x188 magnification. I haven't tried my ST80 yet. Cheers Ian

Hi Reggie Good pic 🙂 Imaging doubles can be fun. Cheers Ian

Hi Michael I have a very similar set I don't have the 7mm I do have the 5mm. They are superb eyepieces. Cheers Ian

Hi Dave, I have always felt the 'colours/hues' are definitely affected by type of telescope. The most vivid colours were in my ST120. The most 'natural' colours were in my 200mm F6 newt. I most definitely peferred the view i the latter Cheers Ian

Hi Stu Yep they look pretty good. 😃 In the 32mm eyepiece you can get about a degree of sky so you can split pairs down to around 2" and get a rich field as well. Cheers Ian

Hi Paul, I'm glad we agree on the colours 😃 Cheers Ian