1 quintuple + 6 double stars in north Orion

Hello everyone. 

It was St. Valentine’s night and I had a remarkably clear sky before Storm Dudley was due to arrive. There was a steady breeze which began at 20km/h – then decreased to 15km/h – only to increase up to 20km/h again before 10.15pm. 
I set up my William Optics 158mm f/7 apochromatic refractor on this Monday evening / night. Indeed the Sun had not fully set as I was preparing for the nights observing with all my equipment with 6 layers of clothing on. All 9 eyepieces were taken out of their boxes and placed on the telescope tray. So it was a case of one big happy family!

Each of these double stars’ figures are from www.stelledoppie.it . And they are all in northern Orion. 
My Bortle is now 8. 
The sky conditions were extremely good and no dew at all because of the breeze. 
Air temperatures decreased from 2˚ to 0˚ Celsius during the 4 hours. I didn’t observe for these 4 hours. That’s because a certain Japanese meal was being delivered at 7.30pm. It’s Valentine’s Day after all. So all in all, I observed for 2 hours 30 minutes. 

1. Where else to start only at Lambda Orionis. STF 738 comprises of 4 stars – and a 5th star somehow has the designation: GUI 9. Can anyone tell me who GUI refers to? Thank you. On then with this multiple star. Magnitudes: A = 3.5. B = 5.5. C = 10.7. D = 9.6. E = 9.2. Sep’s = 4.3”, 29.3”. 78.5” and 151.1”. PA’s = 44˚, 185˚, 272˚ and 279˚. Each star is probably optical to the other. All 5 stars were cleanly seen and separated at 112x. I did notice that the B star had a slight B0 slight blue hue. Each of the other stars were pure white. A lovely sight!

2. Having been challenged on Cloudy Nights to have go at STT 111, I thought it would be a good double to try. I know my scope isn’t the largest by any means. But the separation is well within my limits. Gosh! What a major problem I was to experience. The magnitudes are: A = 5.7. B = 9.7. Sep = 2.8”. PA = 351˚. That separation figure is almost the same as Izar. But in went my 5mm Nagler eyepiece (225x) and I could see nothing of the secondary. With my refractor 351˚ is “straight up”. But even at 280x, 320x and 374x I had no joy whatsoever. I realise there was an almost Full Hunger Moon in eastern Gemini; but over here in northern Orion my “hunger” for STT 111 was not being satisfied. Will it make any difference if the Moon was not in the night sky? I wonder. Why the big delta magnitude difference of 4 would make it a problem double star? So there you have it. No split with STT 111. (Even under the pristine sky).  

3. STF 763 is a true binary east of STT 111. Magnitudes: A = 8.9. B = 9.5. Sep = 6.3”. PA = 319˚. Super tight split at 40x. At 112x I noticed that A is a F8 yellow-white star. B is white. Good sight.

4. STF 726 is an uncertain double west of STT 111. Magnitudes: A = 7.9. B = 8.6. Sep = 1.2”. PA = 264˚. I had 2 stars touching at 225x. I was utterly delighted to see a tiny black gap between the 2 white stars at 280x and 320x. Marvellous! I knew then my sky was extremely good. 

5. 32 Orionis (STF 728) is a true binary. Magnitudes: A = 4.4. B = 5.8. Sep = <1.4”. PA = 44˚. I had successfully separated it quite a number of years ago. It was time to observe it again. I had 2 touching discs at 225x. Beautifully separated at 280x and 320x. And excellent sight as I could make out that the secondary was definitely fainter than the primary. I wrote in my 2022 diary: my favourite double of 2022 so far. 

6. But immediately I wrote the words in my dairy: BUT NO! Because 52 Orionis was next. Magnitudes: A = 6. B = 6. There is precious little difference in their brightness. Sep = <1”. PA = 221˚. Because of the extra tighter separation when compared to 32 Ori, I required 280x and 320x to see there were 2 identical stars extremely close together. But the grandest sight occurred at 374x with my 3mm Radian. A most slender black gap was definitely seen. I don’t have a more powerful eyepiece. However I can say that 52 Orionis is now my most favourite double in 2022 thus far. 

7. STF 724 is an optical double. Magnitudes: A = 9.3. B = 10.6. Sep = 6.8”. PA = 253˚. 2 white stars split at 40x and 112x. A good sight for sure. 

8. Finally STF 817 is very near Betelgeuse. It is a true binary. Magnitudes: A = 8.7. B = 8.9. Sep = 18.6”. PA = 73˚. No problem separating this one at 40x. I noticed that the primary is A5 white; but B is a delightful K orange star. 

Clear skies everyone!

Aubrey.       

Sounds like you had pristine skies alright Aubrey! GUI stands for J Guillaume, an astronomer in Lyon, France during the first half of the 20th century.

Finbarr.

Hi Aubrey, 

Very many thanks for sharing your observations with us. It seems like you had a lovely time under the stars, and to cap it off with a nice meal with Valerie must have been delightful. 

You really pushed the magnification on Monday night.. Wow! As Finbarr said, you must have had pristine skies. Can you imagine what it would have like down at Sugarloaf.... You probably would have split that illusive double - ST 111.

Speaking of the Sugarloaf, I can't imagine tomorrow's meet up will take place considering the forecast. I can't tell you how much I need be back out with my scope. 

Clear skies pal, 

Darren. 

Hello Finbarr. Thank you very much informing us as to who GUI refers to. 
It seems he had a huge long name: Guillaume Joseph Hyacinthe Jean-Baptiste Le Gentil. 

But maybe I'm wrong. That chap above lived in the 18th century. 
I have read in the distant past about a French astronomer who travelled around the world trying to observe a transit of Venus. 

Anyway there might be another astronomer who lived later with the same surname.   

Oh yes. You're so right, Darren!
It would have been highly advantageous to have been at the Sugarloaf. 

By the way, how are you keeping?
It's seems you have had that nasty infection for so long. 

I'm certain you have no trouble splitting either of those tight doubles: 32 and 52 Orionis with your 10" Dobsonian. 

People on Cloudy Nights are encouraging me to try STT 111 some time soon once the Moon has gone into the morning sky. So watch this space! 

If I can cleanly separate 32 Ori, 52 Ori and STF 726 I must be capable at seeing the companion of STT 111. 

Yes. It's time to baton down the hatches for Storm Eunice after midnight tonight.   

Very best regards, Darren and Finbarr. 

Different man Aubrey. Our double star discoverer was Joseph Guillaume, who was attached to Lyon observatory for nearly 40 years and died in 1931.

Clear skies,
Finbarr.

Hi Aubrey, 

It has been almost three weeks since I caught this infection and it has completely floored me. 
Funny you mention about me splitting those doubles in Orion as I was only looking at those doubles in 'Turn Left at Orion' last week. 

But when will we get the chance the observe them? 

Clear skies, 

Darren.