Hunting the Hunter's doubles

[kilix]

Hello,

this is my first ever report.

When I am at the eyepiece I often get the feeling like "I must write this down and let others know what I've seen", but when I return back here, most of the emotions are already washed away and the memory of the event does not seem as exciting. Nevertheless, after many nights mostly strolling around the sky with no purpose, tonight I prepared a lousy piece of paper with instructions from coterless'45 article about Orion.

Actually, I started yesterday by splitting Rigel and Mintaka. Rigel was especially challenging and for a long time it seemed, that it is beyond my reach.  I fiddled with eyepieces and a barlow, but I settled down on 100x magnification with 15mm ES eyepiece, which is my favourite eyepiece with good sharpness, brightness and a nice FOV. Slowly, a very thin light from a companion star appeared. It seemed like a tiny speck of light coming out of a glass fiber, but this glass fiber is as thick as a human hair. Very interesting and the challenge of seeing it was 70% of the fun I had. The more I looked at it, the more obvious it was, in the end I was wondering, how could I have had trouble seeing it, it was obvious. Weird. Do our brains work this way? Or is that the eyes, or the atmosphere cleared up? I have no idea.
Unfortunately, now as I think of it, I don't remember anything about Mintaka. I will have to look at it again later.

Today, I followed the article, so I started with Betelgeuse. Didn't see anything out of the ordinary, there was something wrong with the atmosphere, because the red giant appeared as if someone was twisting my focus knob back and forth. This happened during most of the evening with Tau Ori, Rho Ori, 52, 59 and 33 Ori - all pretty unremarkable and more frustrating than enjoyable (the scope was cooled properly before observing).
Let's skip all the unremarkable moments and focus on what was nice.

Sigma Ori - I spent a lot of time on this and I kept returning to it. Looks great in a 32mm eyepiece at about 47x mag. The "V" shape reminds me of a miniature Aries. There was something happening near the middle three stars. 15mm EP and multiple minutes of gaze, averted gaze, blinking and moving the scope (I'm pretty new to all this, so I am learning the techniques) revealed two tiny specks of light appearing and disappearing near the brightest star. After a long time on the eyepiece, I still can't say for sure if I've seen those two stars, or if that was my brain playing tricks on me. I am like 60% sure that I've seen one of the fainter stars and 20% sure that I've seen both. Interesting. This experience was similar to the experience with Rigel yesterday, those specks appeared at first briefly, then I was almost certain I see one of them comfortably, but suddenly it disappeared, so I doubted my previous judgement and so on.  I will look at Sigma Ori later when the atmosphere is more calm and from a darker spot.

I had also fun looking at NGC 2169. I forgot to look for the shape "37", but it was a very nice cluster nevertheless.

Finally, I turned the scope to M42, as I do every evening these days. Today, it was pretty unremarkable. The shaky atmosphere and/or light pollution made it hard to even see the "D" star from trapezium and the nebula looked more like a foggy eyepiece than like a nebula. I switched to 32mm eyepiece, which gave a better overall look of the nebula, but still, I've seen it better. Then I've put the UHC filter on and oh man! What a change! Today was one of my personal best views of M42! The wings seemed to expand forever, I've seen some nebulosity far away in the southern direction from the trapezium, which I've never seen before, the details in the darker areas seemed to pop right at me and when I didn't look at them directly, they were even more pronounced. Remarkable sight.

 

This report is longer than I wanted it to be, but I feel like I can go on about this even longer. Maybe I will read this again in a year or two and look back to the days when I was beginning.
Clear skies!

[michaelmorris]

Great report on observing just a few of the wonderful array of doubles and other targets in Orion

[Stu]

Great report kilix, nothing wrong with a long report, it gave a really good sense of your discoveries during the session.

Our eyes and brain do work in a remarkable way, teasing out and processing detail in a manner which is hard to understand sometimes. It acts almost like a long exposure, constantly adding information to what you see until you are able to pick out much better detail than when you first started. This applies particularly to planetary observing, the longer you look, the more you see. Each time you revisit these objects you will find it a little easier too.

I suspect much of the focusing issues you were have were simply the atmospheric seeing conditions. When they are bad (which they have been a lot recently) it is very difficult to obtain sharp focus and to see detail. Best option is to get the focus as good as you can, then just wait for the seeing to settle and the detail will pop it at you.

Sigma Orionis is a favourite of mine, there is a quadruple and a triple. In the quadruple there are two stars to one side of the brighter star, then another tiny one the other side. How many did you see in total?

The 37 is well worth another visit too  

Nice first report!

[laudropb]

A very nice and instructive report. It really shows that you have to spend time on these difficult objects, especially when the seeing is not top notch.

[alan potts]

Superb considering it is your first report, of many I hope. The Sigma Orionis is in fact five stars, I have managed a split on the main star but it is very tight at .33, so a large scope is required.

Alan 

[kilix]

great replies and very nice images, Stu!
So my brain was actually playing tricks on me. In Sigma Ori those 2+1 stars on one side (named STF761 A,B and C, as I googled now) were clear as day. In the middle, I've seen comfortably 3 stars (AB, D, E) with 4th popping in and out of existence (most probably C, maybe a hallucination), which I am not very sure about. There was an even dimmer 5th star, appearing even more sporadically, which I now know was actually my brain playing tricks on me  

My image was horizontally mirrored and rotated somewhat compared to yours, but that is probably due to differences in optics Mak-Newt.
Like this:

 

I will return to view this object surely. But it will take some time, yesterday I was too amazed to be aware that it's -16°C and I still feel cold even now. I will have to wait for warmer and calmer weather. I feel that -8°C is warm enough for another session. If it's only -8°C, that will feel like Bahamas compared to yesterday.

[Stu]

Thanks kilix, I wish they were my images but alas they were internet search specials .

Realistically you will only ever see the four stars in Sigma Orionis. Alan is the only person I know who has actually split Sigma itself which is very tough. He does have excellent skies, a wonderful scope and also knows a bit about observing which helps .

For us mortals, the fourth, faint star is a nice challenge but when the seeing is excellent it is lovely to view. Infact, one of my favourite things is viewing stars at the limit of visibility in open clusters like the Double Cluster.

[chiltonstar]

11 hours ago, alan potts said:

Superb considering it is your first report, of many I hope. The Sigma Orionis is in fact five stars, I have managed a split on the main star but it is very tight at .33, so a large scope is required.

Alan 

I have it down as 0.2 arcsec Alan....what year is your figure from??

Chris

[Stu]

1 hour ago, chiltonstar said:

I have it down as 0.2 arcsec Alan....what year is your figure from??

Chris

SkySafari says 0.2", or 0.25" depending where you look.....pretty tight however you put it!

[chiltonstar]

18 minutes ago, Stu said:

SkySafari says 0.2", or 0.25" depending where you look.....pretty tight however you put it!

Stelle Doppie (WDS) gives 0.2 arcsec for 2015; this would need a 500mm scope and a mag of x800-x1000 I imagine.........sounds fun!

Chris

[alan potts]

12 hours ago, chiltonstar said:

I have it down as 0.2 arcsec Alan....what year is your figure from??

Chris

Chris there was a thread on the subject about a year ago, maybe a bit longer, I seem to recall the figure came from that though I am sure I saw it in one of the double lists or maybe Wiki. If I remember correctly you tried it too and got an elongation. If it is .2 it it beyond spliting due to atmostphere I would have thought and beyond even my largest scope and I know I split it.

Alan

[chiltonstar]

2 hours ago, alan potts said:

Chris there was a thread on the subject about a year ago, maybe a bit longer, I seem to recall the figure came from that though I am sure I saw it in one of the double lists or maybe Wiki. If I remember correctly you tried it too and got an elongation. If it is .2 it it beyond spliting due to atmostphere I would have thought and beyond even my largest scope and I know I split it.

Alan

Alan,

This was the older thread I think:-

 

On a night with excellent seeing (not at the moment!!), I see it as slightly oval; maybe worth imaging to estimate the ratio of the two axes.

Chris

 

[alan potts]

5 hours ago, chiltonstar said:

Alan,

This was the older thread I think:-

 

On a night with excellent seeing (not at the moment!!), I see it as slightly oval; maybe worth imaging to estimate the ratio of the two axes.

Chris

 

Chris, I am sure thinking back you only had a go at it based on the thread and accordingly reported back what I have said, it is not the mirror review, it is in observation reports somewhere. I had a stunning sky last night, Sirius still, but I just can't get out because of snow, it is still over 12 inch deep and now compressed, I dare not move the obsey roof as that has about the same amount on it, I can see it being at least another two weeks , even if it starts to melt quicker which it isn't going to do at minus 8.

Alan 

[chiltonstar]

3 hours ago, alan potts said:

Chris, I am sure thinking back you only had a go at it based on the thread and accordingly reported back what I have said, it is not the mirror review, it is in observation reports somewhere. I had a stunning sky last night, Sirius still, but I just can't get out because of snow, it is still over 12 inch deep and now compressed, I dare not move the obsey roof as that has about the same amount on it, I can see it being at least another two weeks , even if it starts to melt quicker which it isn't going to do at minus 8.

Alan 

I can't remember the original observation report - too much Shiraz down the hatch since then! I envy you the snow - I miss the eight years we spent in the pre-Alps!

It looks as though seeing an elongation for me with a 180 Mak was reasonable, judging by this simulation which uses WDS data, and is for x800, and shows just a bit of elongation:-

Chris

[RobertI]

Sounds like you had a great session. I too discovered sigma orionis recently, and was similarly enthralled. I'm also planning on a UHC filter of some kind so good to hear your experiences. Well done on your first report. 

[kilix]

Hello all, this is an update to my quest with the targets in Orion.

So, yesterday was another session dedicated to Orion's double stars and open clusters. I started with obvious M42, what immediately surprised me, was that my SkyMax was not cooled even after staying 30mins outside and another 40min hike in a backpack. It took almost another hour for crisp views to appear. Probably because it was covered in a thick blanket to protect it during the hike.

The obvious target-M42 with my 32mm EP with 47x mag and 1.2° TFOV provided amazing views as always. I focused on Trapezium at 100x and 150x magnification and returned to the Trapezium 3 more times during the night, but still could not resolve the E and F star. Those two stars remain to be seen even after this session. UHC filter showed a lot darker skies and more detail, especially with averted vision. Averted vision is still a pretty new concept to me, I need to practice more.

At first I used the 32mm and 15mm eyepieces, because the view through my 10mm erfle eyepiece was unpleasant, but I've grown fond of it during yesterday's night and used it the most. I found a new appreciation for the EP yesterday. I hesitated to use it before, but now I appreciate it more, maybe my eyes and brain got a bit accustomed to the smaller pupil and tighter eye relief, who knows.

Double stars:
Mintaka - an easy double with surprisingly huge separation at 150x. Did I even spot the right companion star? I am not so sure. The angular size of the gap between those two stars seemed as big as Jupiter at about 100x mag.

Rho Ori / SAO112528 - this one was one of the hardest to spot yesterday. The main star is orange, but it seemed to flicker with blue light when I moved the scope or when I blinked. Something was going on there. What is this effect? I could not spot the companion even after several minutes. I returned to it later and spent many more minutes on it. The faint companion then appeared sporadically to the right of the main star as the seeing conditions allowed. The companion kept on appearing for brief periods of time and then disappearing for longer periods. But I already knew where to look and it became easier to spot. Nice and enjoyable double. I am not sure about the color of the companion, was it blue/white?

Iota Ori / Hatsya / SAO132323 - I liked this one very much. It's in a nice ?open cluster? and one can spend a lot of time trying to spot many faint stars in the same FOV at 150x. I am not sure now, but I think, that there are two triples in the same FOV. Is Hatsya in an open cluster with surrounding stars, or is it just visual cluster and not a cluster in gravitational sense?

Tau Ori / SAO131952 - a triple, with faint companions, challenging to view. Both the companions are faint and jump in and out of view, depending on seeing. Those companions are wider than expected, but really faint. Direct observation of companions is almost impossible, both stars almost completely disappear when viewed directly. I found out now, that one of the companions is actually a double too, but that's out of my reach. Not very enjoyable or memorable to be honest.

I finalized the double stars quest by viewing Rigel, to spot the companion was an easy task, especially after Rho Ori. Quite relaxing after all the eye-strain experienced earlier. I moved on to clusters:

Clusters:

NGC 2141 - I couldn't see anything here. Maybe I did not have correct position, but GoTo has been spot on so far. I don't know.

NGC 2194, NGC 2186 - Same as above, I could see maybe 4-5 stars in the FOV, nothing spectacular happening. Perhaps too faint for my eyes.

NGC 1981 - nice little cluster, pleasing views at 100x. I spent a lot of time viewing the faintest stars on the limit of the resolution of my eyes and my scope.

NGC 2169 - the "37" cluster, definitely worth a revisit. The shape is mirrored in my Mak, that's why I didn't notice the shape the first time around. The top part of the "7" was visible only with averted vision and when I spent a significant amount of time on this object. Very pleasant view at 100x nevertheless.

So, that about sums up my quest for Orion's interesting objects. Many of those will get a revisit certainly (Hatsya, 37cluster, NGC 1981, Sigma Ori, Rigel), maybe all of them will get a revisit now that I think of it

Many thanks to @cotterless45 who summed it all up nicely in his post and inspired me to take a look deeper into Orion. It was very enjoyable and time well spent.

[kilix]

wow, what a wall of text, I apologize, but I feel that writing less would not be adequate.

[cotterless45]

Brilliant !

Alnitak has a close companion at 2.6", then there's the wide companion at 59.8". I caught it in a 4" frac.

For a stunning view, head up to Meissa, lovely multiple group. Don't forget the fish hook of sigma Orionis.

Iota will show the binary Σ747 in the field of view. Hatsya means " bright one of the sword" referring to Orion's sword. ρ Orionis is quoted as tangerine and blue, 4" aperture pulls out a lot of colour here.

Did you spot the bright double Σ848 at the top of the three in NGC 2169 ?

Clear skies !

Nick.

[kilix]

6 hours ago, cotterless45 said:

Brilliant !

Alnitak has a close companion at 2.6", then there's the wide companion at 59.8". I caught it in a 4" frac.

For a stunning view, head up to Meissa, lovely multiple group. Don't forget the fish hook of sigma Orionis.

Iota will show the binary Σ747 in the field of view. Hatsya means " bright one of the sword" referring to Orion's sword. ρ Orionis is quoted as tangerine and blue, 4" aperture pulls out a lot of colour here.

Did you spot the bright double Σ848 at the top of the three in NGC 2169 ?

Clear skies !

Nick.

Yeah, I forgot to mention Sigma Ori and Meissa, Sigma Ori is now my favourite target to view every time I can. To try and find the C star from the cluster. It's a challenge, work in progress, like E and F from trapezium. I believe it only needs more experience.

As for the colour of Rho, well, the orange, or tangerine was clear, but the companion is faint for me to decide if it is blue or white, I barely saw it. Again, may need a bit of practice and time on the eyepiece probably.

As for NGC 2169, I don't know, I was not actively hunting for the double on top of the "3", I did not write that in my observing plan and I did not know about it, but I will check it next time, thanks for the tip.

[cotterless45]

This might help with a fabulous area. Small aperture is wonderful to pick these up and make the most of colour,Clear skies ! 

Nick.