32 and 52 Orionis

[Stu]

I had a go at these two last night with the FC100DC. The seeing was definitely more variable than the night before, but with some moments of better stability quite regularly. Before viewing these, I looked at the Trap and the E star was quite obvious, but F was only giving hints every now and then, nothing definite.

32 Orionis first as it’s the easier at 1.4” separation and 4.23/5.75 magnitude. I found it easily enough using my little RACI, then the 24mm Panoptic and finally popping in a 5mm XW for x148. I thought I was out of luck to start with, but nailing the focus and waiting for the moments of good seeing showed the two airy disks nicely, brighter primary and dimmer secondary at the correct PA. Clear separation when the seeing allowed, a fuzzy blob when it didn’t!

I then gave 52 Orionis a go, and expecting a failure as my understanding of the Dawes limit is 1.16” for a 100mm scope and 52 is 1.0” and 5.3/6.03 mag. The reality matched the theory, I got elongation in the correct direction, best case a peanut shape in the best conditions. I chucked first the 2.5mm TOE at it (x296) and the barlowed it with the Zeiss Abbé Barlow (x592!) and no separation to be seen.

An interesting little exercise.

[Saganite]

Until John recently mentioned 52 Orionis, I had never heard of this double ,so last night I put the 12" Dob onto it, and failed so completely to even elongate it, I doubted I was looking at the correct star. I will have to go again.

[lunator]

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

[Stu]

28 minutes ago, lunator said:

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

Thanks Ian.

By seen do you mean detected ie a notch, or clear separation? I would say I was getting a notch last night and perhaps with better conditions more might be possible.

[Sunshine]

52 Orionis you say? hmm, this is one double I cannot recall trying but when it gets a bit warmer I will for sure! it sounds like a tough one so may require multiple tries till seeing cooperates.

Looking at SkySafari I realized I have gone over it countless times, I have the settings set to highlight doubles it is not doing so with this double, I wonder why it is drawing a small circle around

nearby doubles as I set it too but not 52 Orionis, how many others am i missing? I have to check settings again.

Edited January 14, 2022 by Sunshine

[lunator]

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

[Stu]

11 minutes ago, lunator said:

There are several descriptive terms used such as snowmen, figure of eight.

Thanks again. I went for ‘peanut’ to describe what I saw at its best. I tend to be a bit purist about this and only consider stars are split if I see a black line as a minimum between them, but last night I could definitely see that there were two stars there.

[Zermelo]

I was surprised to split 52 Orionis for the first time on Wednesday, with a Skymax 127 at x375. It was close, but genuine.
I wasn't out last night, but I might have another look tonight.

[John]

I get similar results with these two with my 100mm Tak as well. Close but no cigar on 52. The ED120 got it a couple of nights ago though - that little bit more aperture tips the balance.

Good pair of Winter test doubles these 😀

[Stu]

27 minutes ago, Zermelo said:

I was surprised to split 52 Orionis for the first time on Wednesday, with a Skymax 127 at x375. It was close, but genuine.
I wasn't out last night, but I might have another look tonight.

That’s a good split, and shows the benefit of resolution gained from aperture. I’ve posted before about my Heritage 150p humbling my lovely Vixen FL102S on Zeta Herculis before; it shows nice airy disks whilst the Vixen is more of a brightening on the first diffraction ring. I’m sure the 130mm f6 would split 52 Orionis so will give that a go next time. Going to have a night off tonight even though it looks like it will be clear. Need an early-ish night after all this observing!! 🤪🤪😴😴

[chiltonstar]

100mm is a good aperture for doubles, but good to see that the laws of physics still apply  even in these times of inflation!

Chris

[Stu]

10 minutes ago, chiltonstar said:

100mm is a good aperture for doubles, but good to see that the laws of physics still apply  even in these times of inflation!

Chris

Outrageous I know Chris, I thought because it said Tak on the tube it would split anything! 🤣🤣

[Zermelo]

18 hours ago, chiltonstar said:

100mm is a good aperture for doubles, but good to see that the laws of physics still apply  even in these times of inflation!

Chris

 

But we all knew that, really.

Edited January 15, 2022 by Zermelo