Struve 747 in Orion 

Bob Hogeveen
Star: Struve 747 
Date & Time: November 18, 2000, 00:00 MET 
Seeing: --- <1-10 Seeing Scale (10 best)>
Location of site: Annen, The Netherlands
(53 N, 6 E)
Site classification: Village-backyard
Sky darkness: 4 <Limiting magnitude> 
Conditions: Some clouds 
Temperature: 5ºC 
Binocular: Swift Supreme 10x50 (on tripod)


One of my favorite doubles for bino's and small scope. 

Struve 747 is an attractive little double, bright enough for comfortable observing, close enough to give the "real double feeling", and not to close to make it difficult. 

It's position in one of the most beautiful and interesting starfield in our sky, Orion's sword, makes this a real showstopper. In the same FOV we see the nebulous glow of M42, the Great Orion nebula. Several doubles can be seen in this FOV : 

Theta-1+2 and Theta-2 itself are doubles embedded in the glow og M42. Theta-1 is the famous Trapezium; with the bino it can be detected that something is going on there, but the stars are to close for real separation. 

To the north of M42 we have the very wide pair 42+45 Ori, not really interesting in itself, but they add to the beauty of this field. 

With my 8cm Swarovski this field and these doubles are even more spectacular. With 20x the whole area form 42+45 to STF747 is still in one FOV. M42 is much more obvious, the stars in the field are brighter and Theta-1 begins to resolve... 

Tim Leese
Star: Struve 747 
Date & Time: 20-November-2000 (23:35UT)
Seeing: 7-8 <1-10 Seeing Scale (10 best)> 
Location of site: Cheshire. UK
53° 15' N –2º 33' W 
Site classification: Suburban 
Sky darkness: 4 <Limiting magnitude>
Conditions: Very clear and still sky between clouds. 
Binoculars: 12X50 Olympus 5.3deg FOV
(hand held)


These two stars were located at the bottom of the sword which showed just a hint of nebulosity in the view of the binoculars. Struve 747 was separated into a pair of sparkling jewels against the remarkably steady dark sky. 


Eddy O'Connor
Star: Struve 747 
Date & Time: Dec 5th 2000. 10 -11p.m local; UT +11 
Seeing: 5-6 <1-10 Seeing Scale (10 best)>
Transparency: 6/10 
Temperature: 18ºC 
Other Conditions: Calm. Moon 9 days old 
Location of Site: Terara, New South Wales 
Australia,  S34.52, W150.38 degrees. 
Site Classification: Suburban 
Sky darkness: North 4; South 4.5 <Limiting magnitude> 
Binoculars: 7X35 Tento. 25X100 Somet. 
(Occasional 16" Dob comparisons ) 
HS: 1 
HS= Harshaw Scale1-5 (1 best) 
We now enter the southern tip of Orion's sword, that most impressive fiery forge of new stars. This is a show-piece double in binoculars, with skies darker than tonight revealing veils of white gas surrounding these opal-like stars. A White primary and 
Bluish companion does not do justice to such a rich display in binoculars. 

Comments: This field yields more by the minute, with a faint triangle of stars surrounding the primary in the 25X100. A rich field and worth revisiting. 


Thad Robosson
Star: Struve 747 
Date & Time: 1-17-01, 3:30 - 5:30 UT 
Seeing: 4~5 <1-10 Seeing Scale (10 best)> 
Weather: clear, but quite chilly at 45°F 
(Hey, it's cold to us....) 
Location of Site: Phoenix, AZ 
112 08.029w, 33 32.674n 
Site Classification: Suburban 
Sky darkness: -- <Limiting magnitude> 
Transparency: 3~4/10 
Binoculars: 10x50 on homemade bino mount. 
PA at around 225°.  White with Blueish comp.  Slight mag. difference. 


Luis Argüelles
Star: Struve 747 
Date & Time: 11, February, 2001, 19:25 UT
Site of Observation: Far suburbs of Gijon, Spain
Site Clasification: Suburban
Seeing: About 8 <1-10 Seeing Scale (10 best)>
Sky darkness: About 4 <Limiting magnitude> 
Transparency: 5 
Temperature: About 12ºC 
Conditions: Some very light fog. 
Binoculars: Pentax PCF-V 8x40, 6.3º field. Tripod mounted. 
Finding this double is a childs’ play since M42 first and the Iota Ori are two excellent celestial beacons. From beautiful Iota, it’s located a bit towards South and West. Primary is white and secondary is cleary fainter than primary. 

Ambience: Initially it wasn’t on my plans to make some observing today except some Birding in the Pond Gijon’s Park, thus the 8x40, but our friend Angela invited us to coffe in her house (she has a beautiful garden) and we decided to show her some beauties in Orion and also Taurus and Gemini naked-eye. Incidentally she showed a natural aptitude for detecting coloration and this first night for her, she easiliy identifiy Betelgeuse by herself after showing her Aldebaran: “Hey, another giant red there, right?”. 

Her dog Lola rehuses company as usually and her 3 cats look at us with a strange face. 

Carol Locomiak
Star: Struve 747
Date & Time: UT Feb 14th, 01:00 till 04:00
Seeing: 7 <1-10 Seeing Scale (10 best)>
Transparency: Very good 8/10 
Temperature: 20°F 
Other Conditions: Slight breeze; no Moon
Location of Site: Tomahawk WI, USA
45ºN 89ºW
Site Classification:  Rural
Sky darkness: 8/10
Binoculars: Oberwerk 22x100
Sep. 35.70" // mags 4.78 and 5.6
Primary white w/ hint of foam green, secondary white w/ very light touch of baby blue. 
Just a comment here.. in congested stellar areas on charts it would help a lot if the brighter stars were printed as smaller dots but with the magnitude listed. The common 'overbloating' of their size makes it very difficult to figure out what's what sometimes. I was using the Sky Atlas 2000 charts which includes an Orion enlargement; even so, it took me a while to 'unlayer' the stars. 

Paolo Morini

Star:Struve 747 (Ori)
Date & Time: Jan 10, 2006, 21:00 UTC 
Seeing: --
Location of site: home, Ravenna, Italy
Site classification: Urban backyard 
Sky darkness: 3.5 <Limiting magnitude> 
Temperature: 2° C
Binocular: Miyauchi 30x77

Very nice, Moon brightness, PA checked - a crowded binoculars field