Otto Struve 410 in Cygnus

Richard Harshaw
Star: Otto Struve 410
Date & Time: Enf of July, 2001
Seeing: 8 down to 6 <1-10 Seeing Scale (10 best)>
Transparency: 7 down to 5 <1-10 Transparency Scale (10 best)>
Temperature: 30ºC ( 86ºF)
Location of site: Kansas City, USA
Site classification: suburban 
Sky darkness: 4.5 <Limiting magnitude>
Telescope: Celestron 11" SCT f/10
Eyepiece: 5mm Lanthanum 
Magnification: 560x 
Harshaw rating: 2
W and W, rated 2.  Nice pair, with crisp black sky between the disks.


Thad Robosson
Star: Otto Struve 410
Date & Time: Aug 25th, 2001
Seeing: 6 <1-10 Seeing Scale (10 best)>. 
Transparency: 7
Location of site: Cherry Rd., USA
34 31.136N, -112 05.078W
Elevation: 4435 Ft
Site classification: Rural
Sky darkness: -- <Limiting magnitude> 
Conditions: Clear, with 1 rst quarter moon lighting the way
Telescope: 8" f/6 Newtonian on EQ mount. 
Eyepieces: TV 5 Radian
Magnification: 240x 
Nearly equal pair of blue white stars. Seen as split most the time. PA near 15.  Rated a 2.


Jim Phillips
Star: Otto Struve 410
Date & Time: September 21, 2001
Seeing: 8 <1-10 Seeing Scale (10 best)>. 
Location of site: Charleston, South Carolina USA
Site classification: Suburban
Sky darkness: -- <Limiting magnitude> 
Temperature. 82º F, Hazy
Telescope: 9" F/15 apo Astrophysics refractor (folded design)
Eyepieces: 16mm & 2X Zeiss
Magnification:  428x

Star: Otto Struve 410
Date & Time: July 19, 2002
Seeing: 6-7 <1-10 Seeing Scale (10 best)>
Transparency: 5 <1-10 Seeing Scale (10 best)>
Location of site: Greenwood, South Carolina USA
Site classification: Suburban
Sky darkness: 3.0 <Limiting magnitude> 
Telescope: TMB 8" F/9
Eyepieces: Binoviewer with and without  barcon
plus extension (3.2X)Zeiss abbe orthos, 4mm, 10mm, 16mm and 34mm Brandons, 12mm
Magnification: 365x

White, white. Split with 16mm & 2X Zeiss (428X).
Clean split.

Nice split with 16mm plus barcon plus extension = 365X


Luis Argüelles
Star: Otto Struve 410
Date & Time: 11 July, 2002, 22:30 UT
Seeing: 7 <1-10 Seeing Scale (10 best)>. 
Transparency: 5-
Location of site: Quintueles, near Gijon, Spain
Elevation: 20 m.
Site classification: Suburban garden
Temperature: 16.8ºC
Humidity: ~ 75% (less than 1 km from sea)
Sky darkness: 3-3.5 <Limiting magnitude> 
Conditions: Lots of light pollution from Gijon at west. Clouds rolling from there.
Telescope: Takahashi FS-102
Mount: Vixen GP w/Skysensor 2000
Eyepieces: 5mm Eudiascopic + 2x Celestron Ultima barlow
Magnification: 328x

Date: 24, July, 2003 , 12:10 -> 2:00 local time
Location of Site: Sena de Luna, Spain
42.55N, 05.57W
Seeing: 9 -> 6 <1-10 Seeing scale (10 best)>
Transparency: 8 -> 5 <1-10 scale (10 best)>
Other conditions: No Moon. 
Altitude: 1,200 mts (3,940 ft)
Site classification: Rural
Sky darkness: about 5.5
Telescope: Takahashi FS-102
Mount: Vixen GP + Skysensor 2000
Eyepieces: 9mm Nagler, 5mm and 3.8mm Eudiascopics. Celestron Ultima 2x Barlow
Diagonal: Zeiss prism diagonal
Magnifications: 91x, 164x, 215x, 328x

Only in the best moments of seeing I think to suspect a very small “feel” of duplicity. With the actual observing conditions I’m unable to destilate more info from this tight double.

Ambience: The near Cantabrian sea is less than 1 km away and the tide must be high, because I hear the waves coming to the beach when the dogs stop barking. First night of observing (when I had a lot of problems with the Takahashi focuser –very loose for heavy eyepieces-) they were “non-stop” barking. Now they seem more familiar with me.
After centering it with the 9mm Nagler, I switch to a 3.8mm Baader Eudiascopic, observing the tinniest elongation on this nut. After inserting a 5mm Eudiascopic + 2x Celestron Ultima Barlow, a difficult elongation is confirmed. Although the image is not constant, other experiences tell me that I’m observing a double. Color seems to me to be yellowish. The star forms a right-triangle with other two stars. Otto Struve 410 is located (vertex) at the right angle of the triangle. Very difficult double, but achievable when seeing is, as today, less than 1 arcsecond.


Inge Skauvik
Star: Otto Struve 410
Date & Time: 18.Aug.02 0100 - 0230
Seeing: 8 <1-10 Seeing Scale (10 best)>. 
Transparency:  Poor/moderate
Location of site: Haavik, Norway
Site classification: Suburban
Temperature: +15º C
Sky darkness: 5.0 <Limiting magnitude> 
Conditions: Wind 2 - 8 m/s from the south
Telescope: 8-inch Portaball with Zambuto mirror
Mount: Dobsonian type
Eyepieces: 16 mm Konig, 7 mm Ortho, 5 mm
Ortho, 2.8x Klee Barlow (all > University Optics)
Magnification: 240x / 480x
This is the brightest star in a group of three forming a small triangle. Separation is obvious at 240x power. Clean, nice split was achieved at 480x. Components nearly equal in magnitude.


Steve Bodin
Star: Otto Struve 410
Date & Time: 22-24 Sep 2002,
9pm to 11pm
Seeing: 4-5 <1-10 Seeing Scale (10 best)>
Transparency: fair, some hi-cirrus
Location: Silverdale WA, USA
Site classification: Suburban
Sky darkness: 4 <Limiting magnitude>
Telescope: Celestron C8
Imaging: PC164C video camera, 6x barlow
Eyepieces: 24mm konig, 18 ortho, 12.5 ortho, 7 ortho
Magnification: 80x,110x,160x, 285x
Magnification (imaging): 333x prime focus, 2000x with 6x barlow
This one split easier than Lambda Cygni with the 7mm ortho at 285x due to the equal magnitudes of the components. At 80x the C and D components are obvious. Again all seem blue or blue-white. Measurements: AB 0.87 seconds at 005.3 deg PA with 6x magnification, AB-C at 69.61 sec at 069.7 deg PA, AB-D at 107.2 sec at 326.4 deg PA both at prime focus.