Otto Struve 503

Richard Harshaw 
Star: Otto Struve 503
Date & Time: September 5, 2001,
0230 to 0510 UT
Seeing: 6 <1-10 Seeing Scale (10 best)>
Transparncy: 6 to 7 (variable, due to high hazy clouds) <1-10 Seeing Scale (10 best)>
Location of site: Northern Kansas City,
Missouri (USA). 39º15' N, 94º30'W
980 ft above Mean Sea Level
Site classification: suburban 
Sky darkness: -- <Limiting magnitude>
Telescope: Celestron C-8, C-11
Magnification: 560x
Harshaw Scale: 3 <1-5; 1 best>
HD Number 222610
 SAO Number 91425
 ADS Number 16937
Position:  2342+2017  Rating:  3
 A:  7.6m, F8
 B:  8.7m, 1.4 -” @ 133 
Year of last AB Measure:  1978
Distance (l.y.): 400, Luminosity (Suns): 16
Observed colors:  Y, Y 

Observations: Observed at 560x.  W and W, and not an easy pair to split!
It is the W-most star of a distinctive flat triangle with two other 8m stars.

Notes: First measure:  1.8" @ 133.

Jim Phillips
Star: Otto Struve 503
Date & Time: Oct. 17, 2001
Seeing: 5-6 <1-10 Seeing Scale (10 best)>
Location of site: Hodges, South Carolina, USA
Site classification: Suburban.
Temperature: 59ºF
Sky darkness: --- <Limiting magnitude>
Telescope: AP 9" F/15 Apochromat
Magnification: ---
Seeing not good. Split but lots of turbulence. White, white.



Jim Jones
Star: Otto Struve 503
Date & Time: 10/18/01
Seeing: 6 <1-10 Seeing Scale (10 best)>
Location of site: Lake Oswego, Oregon
Site classification: Suburban.
Sky darkness: 4.2 <Limiting magnitude>
Sky: New moon + 1 days.
Telescope: 8" LX50
Eye Pieces: 18mm Radian, 12.5mm CMG, 7mm Ortho, 2x Ultima
Magnification: 112x, 160x, 224x, 285x.
Companion to the SE of Primary.
The seeing is very variable. Observed intermittent separation at 160x, 224x and 285x.  Seeing wouldn't support 570x. Observed the best separation using the 12.5mm CMG (160x).  Very clear, crisp separation  for about 30 seconds and then the seeing changed and we went back to intermittent separation. I find that the 12.5mm CMG is a good eyepiece in its own right and it sometimes performs very well. Too bad it has all that writing on the lens.