Xi Ursa Majoris (Struve 1523)

 
Steve Bodin 
Star: Xi Ursa Majoris (Struve 1523)
Date & Time: 1 Mar 2003 9 pm to 11pm local
Seeing: 6->4  <1-10 Seeing Scale (10 best)>. 
Transparency: poor
Location of site: Silverdale WA, USA
47N 123W
Site classification: suburb-rural
Conditions: temp 40F, some dew
Sky darkness: 5.5 <Limiting magnitude> 
Telescope: Celestron C8
Eyepieces: not used
Additional: DX-8263SL video camera at prime focus and 3x
Magnification: app. 333x, 1000x video		 One of my favorite UMa stars. This star is in conciderable motion and I have seen 20 deg of PA swing in the last few years. Creamy white primary and blue-white secondary. Measurement with the C8 and 3x barlow; 1.81 sec at 253.3 deg PA.













 

 
William Guyot
Star: Xi Ursa Majoris (Struve 1523)
Date & Time: 10th, March, 2003, 01:00
Seeing:  7 <1-10 Seeing Scale (10 best)>. 
Transparency: 
Location of site: Clermont-Ferrand, France
Site classification: suburb-rural
Temperature : 5°C: 
Sky darkness: ~5 <Limiting magnitude> 
Telescope: Vixen 80ED
Eyepieces: LVW 17mm, LVW 8mm , barlow ultima X2
Magnification: X42,  X90, X84, X180		 barely seen with LVW 8mm, clearly splited with LVW 8mm + barlow X2 (X180). It was for me a nice 8. My better double of the night :)
 
 

 

 
Tom  Teague
Star: Xi Ursa Majoris (Struve 1523)
Date & Time: 2003 March 14 (22:30 UT)
Seeing: 6-7 (very variable)
<1-10 Seeing Scale (10 best)>. 
Transparency: 
Location of site: Chester, UK
53º 11' 08"N, 02ºË 51' 39"³W
Site classification: Suburban
Conditions: Clear, cold, still.
Sky darkness: Poor (gibbous Moon)
Telescope: 2.5 inch Zeiss Telementor refractor 
Mount:  Zeiss T-mount
Eyepieces: 
Magnification: x34, x84, x140, x210
Harshaw scale:  <1-5 Scale (1 best)>
   		 Single x34. Clearly double at all powers from x84 upward.

During moments of better seeing, it appears as a figure-of-eight, with two slightly overlapping discs.

Estimated PA is about 260º. The current orbital prediction gives a separation of about 1.8", but although this is a pair with a securely established orbit, I find it hard to believe that it isn't rathercloser @ say 1.5".

It should be just resolvable in my Telementor, but I see the two discs as overlapping rather than tangential. Perhaps the seeing is to blame for my failure to split them cleanly.I could not detect any colours, although the difference in brightness betweenthe two components was obvious enough. I found the most pleasing view was at apower of x140, but in steadier conditions I would expect x210 to be even better.
 

 
Luis Balanzino
Star: Xi Ursa Majoris (Struve 1523)
Date & Time: Mar 11-12, 2003, 20h to 22h UT 
Seeing: 6 <1-10 Seeing Scale (10 best)>. 
Transparency: 6 <1 worst - 10 best> 
Location of site: Göteborg, Sweden
57°43' N, 11°58' E 
Site classification: Urban area with
considerable light pollution 
Moon: In Taurus, illuminated fraction 0,55
Temperature: 2º C 
Sky darkness: 4.5 <Limiting magnitude> 
Telescope: Meade ETX-90 MK 90mm f/13.8 on photo tripod
Eyepieces: 26mm Meade 4000 and 12,5mm TAL Super Plossl, 2x TAL Barlow 
Magnification: 48x, 100x, 200x
   		 Easy to identify but hard to split in the ETX. In fact, the separation is not far from the Dawes limit for this scope. At 48x no split at all, but at 100x I can see two very bright, small dots of light in contact, nice! They look white or slightly yellowish. Switching to 200x show the stars almost in contact, but the conditions aren't good to use high power.
 
 
 
 
 
 

 

 
Tim  Leese
Star: Xi Ursa Majoris (Struve 1523)
Date & Time: 22 March 2003, 22:30 UT
Seeing: 6-7 <1-10 Seeing Scale (10 best)>. 
Transparency: 
Location of site: Northwich, Cheshire. UK.
(53° 15' N -2º 33' W).
Site classification: Suburban
Conditions: Clear sky, light low mist, no Moon visible.
Sky darkness: 3.0 ( Umi ) <Limiting magnitude> 
Telescope: 4inch f/15 Vixen: achromat.
Mount:  EQ5
Eyepieces: 18mm and 9mm Orthoscopics, X2 barlow.
Magnification: X83, X166, X332
    		 9mm Or-------A definite sighting using this magnification. The seeing was wavering, but for odd moments, I could see a clear split of the two pale yellow stars.

9mm Or +X2 barlow-----When the boiling image settled, a definite split with the companion estimated to be at about the 270degree mark. I enjoyed observing this double as it takes high power well.

As I was searching for this double I chanced upon another double, nearby ( since identified as STF 1524). Another,  very faint and delicate, bluish companion, glimpsed with an orangey/yellow primary.A bonus!!
 
 
 

 

 
William Guyot 
Star: Xi Ursa Majoris (Struve 1523)
Date & Time: 25 mar 2003, 22 to 24h
Seeing: 4->6 <1-10 Seeing Scale (10 best)>. 
Transparency:  medium
Location of site: La Garandie near
Clermont-Ferrand, France
Site classification: suburb/rural
Temperature: 8°C, now dew
Sky darkness: 5.3 <Limiting magnitude> 
Telescope: AP Traveller EDT
Eyepieces: Clavé 12/20/25mm, vixen LVW 8mm, Powermate X5
Magnification: X24, X36, X51, X76, X122, X153, X254		 Very nice quite equal pair very white. Barely splited with X122, 
splited nicely with X153
 
 
 
 
 
 
 
 

 

 
Tom Campbell
Star: Xi Ursa Majoris (Struve 1523)
Date & Time:  April 1, 2003,
8:25pm - 10:00pm CST (02:25-04:00 UT)
Seeing: 7 <1-10 Seeing Scale (10 best)>. 
Transparency: 7 <1 worst - 10 best> 
Location of site: Iola, Kansas
Long: 95°24'W, 37°55'N
Site classification: Suburban
Temperature: Temperatures in the lower 60s
. There was a moderate breeze.
Sky darkness:  <Limiting magnitude> 
Telescope: Discovery DHQ 8" dobsonian
Eyepieces: 1.25" Plössls - 25mm,, 15mm, 10mm,
6.5mm, 4mm
Magnification: 49x, 81x, 122x, 188x, 305x
    		 Both stars in this pair are about equal brightness, and both are yellow-white. At 305x, I could barely split them.
 
 
 
 
 
 
 
 

 
 
 
William L. Schart 
Star: Xi Ursa Majoris (Struve 1523)
Date & Time: Saturday, 25th of April, 2003
Seeing: 8 <1-10 Seeing Scale (10 best)>. 
Transparency: 
Location of site: Texas, USA
Site classification: Suburban
Sky darkness: 4 <Limiting magnitude> 
Telescope: C8
Eyepieces: 
Magnification: 		 A tight pair, but rather bright, hence not an overly 
high DI of 72.64. There was a slight elongaton at low power, definately 
elongated and perhaps even notched at mid power and clearly split at 
high power.

   
 
 
 

 

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