Otto Struve 256 

Richard Harshaw
Star: Otto Struve 256 (OS 256 App; HD 332; SAO 53668) 
Location of site: Northern Kansas City, Missouri (USA) 
94d 30m west longitude, 39d 15m north latitude 
980 ft above Mean Sea Level 
Date of observations (UT): 03:30, Oct 17, 2000 
Site classification: suburban 
Sky conditions: 
seeing-- 8 out of 10 
transparency-- 7 out of 10 
limiting visual magnitude-- 4.5 mag 
Telescope: Celestron C-8 
Eyepiece: 12.5mm MicroGuide (166x) 
 
 		 The OS 256 shown on the 33 Site's list is actually a pair at 12:56-00:57.  The list should have listed this as OS 256 App (or, in some catalogs, OSS 256). 

Sep/PA's:  110" / 115 
Year of last measurement:  1923 
Distance (light years):  398 
Luminosity (in suns):  33 
Eyepiece and magnification:  12.5mm MicroGuide (166x) 
Colors noted:  W and W. 

Very easy pair— too easy to be a challenge, really.  It is not a true binary, but merely an optical double.  Not worth rating. 
 
I made six pairs of separation and PA measures using the Micro-Guide 
and got an average of 115.9" in PA 111.7. 
 
 
 
Tom Teague
Star: Otto Struve 256 
Date & Time: 2000 October 18 (20:05 UT) 
Seeing: 6 <1-10 Seeing Scale (10 best)>. 
Location of site: Chester, England (53 11 08N; 02 51 39W) 
Site classification: Suburban  
Sky darkness: 4 <Limiting magnitude> 
Telescope: 63mm Zeiss Telementor refractor 
Magnification: x47 
 		 Wide, equal pair.  Both components appear white.  Boring. 
 
 
 
 
Ilario Melandri
Star: Otto Struve 256 
Date & Time: 1 nov 2000 , 20.09 UT 
Seeing: 6 <1-10 Seeing Scale (10 best)>  
Location of site: Italy, Ravenna, San Romualdo, Lat 44 32’N Lon 12 08’E 
Elevation: 0 m 
Site classification: Rural  
Sky darkness: 4.5 <Limiting magnitude> 
Temperature: +9C 
Telescope: 150 mm f/15 achromatic refractor (lens by Romano Zen, Venice). 
Magnification: 140x (Plossl 16mm)