Struve 2470 

Richard Harshaw 
Star: Struve 2470 
Date & Time: 6 July, 2001, 03:00 to 04:55, UT
Seeing: 8 <1-10 Seeing Scale (10 best)>. 
Transparency: 6-7/10 ,variable, due to high hazy clouds 
Location of site: Northern Kansas City, Missouri. 39º 15' N, 94º 30' W, 980 ft above Mean Sea Level
Site classification: Suburban
Sky darkness:  <Limiting magnitude>
Telescope: Celestron C-11
Eyepieces: 25mm Plossl 
Magnification: 112x		 Position:  1909+3445 
Magnitudes:  7.0 (B3 V), 8.5 (A2) 
Sep/PA's:   14+ / 268- 
Year of this measurement:  1983 
Distance (light years):  1,320 
Luminosity (in suns):  255 
Colors noted:  yW, pB 

Comments:  Webb saw them as W and pB.  Very pretty!  STF 2474 to the SW is a nice addition! 
Rating:  2 

 
Jim Jones
Star: Struve 2470 
Date & Time: 07/06/01 0613 UTC
Seeing: 6 <1-10 Seeing Scale (10 best)>. 
Location of site: Lake Oswego, Oregon
Site classification: Suburban
Sky darkness: 5.0 in Lyra <Limiting magnitude>
Sky: Full Moon very bright sky
Telescope: 8 inch LX50 SCT 
Eyepieces:  18mm Radian 
Magnification: 112x		 STF2470/2474 deserves special comment. I moved from Gamma Lyr to STF2470 via analog setting circles. I was vaguely aware of the "second" double-double in 
Lyra abut had never observed it and didn't make the connection with these two doubles.  So when I looked through the eyepiece I had a real surprise coming. 

It was great.  It knocked my socks off.  For me, the immediate resemblance to Epsilon Lyr was striking. Then I began to see the differences. The doubles are parallel rather than perpendicular. They are somewhat dimmer. To my eye they were much more colorful. 

All four stars appeared blue even though 2474 spectral types are G1 and G5.  I'll have to take another look when lighting conditions are better. They are somewhat wider but not so wide as to lose the effect of the double-double. Great pair. 

Est PA without inst...275d 
Taken with STF 2474 this is another double-double 
in Lyra.  Both stars of STF 2470 were bright blue. 
Very colorful as the sky gets darker.  STF 2470 
is a bit dimmer and closer than STF 2474. 

Ambiance:  Thursday was a fine day. So good that we took our grandson for a walk along the banks of the Willemette River. Thursday evening was an extension of the day.  Warm with a gentle breeze.  Quiet except for the neighbor kids (some of which are at least 35) setting off fireworks left over from the 4th from time to time. 

A full moon back lights the fir grove to the south creating a deep shadow across our backyard.  Nothing much stirring.  I wonder what happened to my skunk? 
 

 
Bob Hogeveen
Star: Struve 2470 
Date & Time: July 8, 2001; 0:30 - 01.15 
Seeing: 6 <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>
Telescope: Meade SCT 8" f/10 
Eyepieces: Ultima 30 mm, TV plossl 20mm, LV 15mm, LV 7mm 
Magnification: 133x		 Together with STF2474 another double-double in Lyra. Nice view when both doubles are in 1 FOV. With a mutual distance of 10' both doubles are in the same FOV even with 133x. STF2470 is an easy and pretty double. Star A shows a bit bluish. 
Rating: 2 

 

 
William Schart 
Star: Struve 2470 
Date & Time: July/9/01 0500 to 0635 UT
Seeing: 7 <1-10 Seeing Scale (10 best)>. 
Location of site: Killeen, TX, USA
Site classification: Suburban
Sky darkness: 4 <Limiting magnitude>
Temperature: In the 80's F (30's C). Slight breeze. 
Telescope: Celestar 8" SCT
Eyepieces:  25mm, 17mm, 10mm 
Magnification: 80x, 120x, 200x
 

Star: Struve 2470 
Date & Time: August 4, 2001, 9:25 to 10:12 pm CDT
Seeing: 7 <1-10 Seeing Scale (10 best)>
Location of site: Killeen, TX, USA
Site classification: 
Sky darkness: 3.5 <Limiting magnitude> 
Temperature: 89ºF (32ºC). 
Telescope: Celestar 8" SCT 
Eyepieces: 12.5 Microguide EP 
Magnification: 160x
 

 The other "double double" in Lyra. These are 2 very similar appearing pairs and visible in the same FOV. They are not quite parallel and the comapnions are both on the same side of the primary. 2470 is more blue to me. 2474 I see as blue for the primary and yellow for the secondary. 
 
 
 
 
 
 
 
 
 
 
 

Sep: 14.9, PA 268.8 (ave 5 meas)
 

 
Mary Flanagan
Star: Struve 2470 
Date & Time: 
Seeing: 6 <1-10 Seeing Scale (10 best)>. 
Transparency: 9/10 
Location of site: Apple Valley MN, USA
93d 14m 25s W; 44d 45m 17s N
Site classification: Suburban
Sky darkness: ~4.5 <Limiting magnitude>
Telescope: 12.5" f/5 Dobsonian 
Magnification: 50x		 As others have noted, this is another "double-double" . . . without the separation issues, and with nice colors.  2470 was creamy white with a pale blue secondary; I saw pale orange and blue for 2474.
 

 

 
Bill Reinehr 
Star: Struve 2470 
Date & Time: July 18, 2001 03:30  UTC
Seeing: 8 <1-10 Seeing Scale (10 best)>. 
Location of site: Pflugerville, Texas, USA (30 degrees N.)
Site classification: Suburban
Sky darkness: 4.2 <Limiting magnitude>
Temperature: 82º F. 
Telescope: Vixen 80mm Fluorite, f/8  on Custom D altaz mount
Magnification: 26x & 46x. (25mm Ultrascopic & 14mm Orion LV)
: 		 In the same FOV as STF 2474. Barely but cleanly split at 26x. More interesting at 46x.   A less challenging version of the double-double (epsilon lyrae). The arrangement of the components differs from that in the double-double. The components in epsilon lyrae are perpendicular but these are almost exactly parallel. No colors noted.
 
 
 
 
 

 

 
Tim Leese
Star: Struve 2470 
Date & Time: 16 July 2001 ( 00:40 UT ).
Seeing: 7 <1-10 Seeing Scale (10 best)>. 
Location of site: Northwich, Cheshire. UK. 53° 15' N -2º 33' W. 
Site classification: Suburban
Conditions: Clear spell, cool, no Moon.
Sky darkness: 4.2 ( UMi ) <Limiting magnitude>
Telescope: 200mm f/6  Newtonian reflector. Mounted over a Vixen GP mount (manual slow motion).
Eyepieces: 18mm and 9mm orthoscopics.
Magnification:  X67, X134		 Using an orthoscopic eyepiece at X67 revealed a  nice view of 4 stars very similar  to the more famous "double double" surrounded by fainter stars in the same field of view. This pair are more widely separated than Epsilon making them slightly harder to find in the finder scope but once I had them in view the stars were easy to separate into their components.

At X67 the more  southerly pair( STF 2474 ) appeared to my eye as having a very pale yellow colour with the other pair( STF 2470 ) appearing white.

I could only just get the four stars in the same fov using X134 but the colour contrast seemed more apparent. At this magnification STF 2470 appeared to be white with a blue/white companion. STF 2474 appeared to be pale yellow with a yellow orange companion.  Two very pretty double stars in the same low power field of view.
 

 
Stuart Clough
Star: Struve 2470
Date & Time: 27.07.01. 2135 UT
Seeing: 7 <1-10 Seeing Scale (10 best)>. 
Location of site: Near Halifax
West Yorkshire, England.
Site classification: Suburban
Sky darkness: 4.4 (U Mi) <Limiting magnitude> 
Temperature: 22 C
Conditions: No cloud, Lt. Airs, balmy.
Telescope: Orion Optics UK GX250
10"  f4.8 Newtonian on Vixen GP mount.
Eyepieces: 20 mm Plossl, 25 mm Ortho, Ultima Barlow
Magnification: x60, x 96		 My first look at this star with its companion STF 2474. Certainly these stars are as attractive as Epsilon and the similarity of the position angle in both adds to the effect.

Split easily at x60, best view at x96.. STF 2470 was seen as having blue and white components, whilst STF 2474 showed pale yellow with a yellow comes.

 

 
Philippe Dejocas
Star: Struve 2470
Date & Time: August 8 2001 
Seeing: 9 <1-10 Seeing Scale (10 best)>
Location of site: Canada
Site classification: Suburban
Conditions: Clean skies and warm temperatures.
Sky darkness: 4.5 <Limiting magnitude> 
Telescope: 6inch/f5 newt
Magnification: 40x

 

 The double/Double counterpart easy at 40x STF 2470 est. @ 10" - W/WWS (WDS: 13.8" - 269°), STF 2474 @ 12" - WWS/W (WDS: 16.2" - 263°). A sure *** for both.
 
 
 

 

 
Tomás Vázquez 
Star: Struve 2470
Date & Time: 22/04/2001. (TU): 02:44:17
Seeing: 4 <1-10 Seeing Scale (10 best)>. 
Location of site: Sevilla. Spain
37 24 N. 5 58 W
Site classification: Urban
Sky darkness: 3 <Limiting magnitude>
Telescope: C8. Reducer Focal: F/6,3
Eyepieces: CCD Camera
Magnification: n/a

 

 Observation: Camera CCD ST-4.
Time of Integration: 10 seconds.
Software Lectura CCD: LUCAS 1.1
Software Treatment: LAIA 3.2A
Position Image: North up, Este left.
Telescope Computer Interface: MICRO-GUIDER III.
Planetariun and Telescope Control Program: ECU. "Earth Cerntered Universe"

Description: The measures that I have carried out from the Amgle of Position and Separation to this double are the following:

AP: 269.75º D: 13.54"

Data Catalog WDS.
AR: 19h08m48.00s DE:+34°46'00.0"
STF2470
m: 7.00/ 8.60
1829: 12.9"/271°
1995: 13.8"/269°
Sp:B5V Np
DM:+34 3437
 

 
Jim Phillips
Star: Struve 2470
Date & Time: August 18, 2001, 9:30-11:05 PM EDT
Seeing: 8 <1-10 Seeing Scale (10 best)>
Location of site: Hodges, SC, USA
Site classification: Suburban
Sky darkness: 2 <Limiting magnitude> Much lightening virtually nonstop on Southern and western horizon. 
Temperature: 73 degrees F.
Conditions: Very hazy. Flashes up to Antares. Quite a light show with occasional flashes lighting up 
the observatory. 
Telescope: AP 155 F/7 Apo
Magnification: 68x

 

 Two doubles are in the same field and both are                   similar! Beautiful view with 16mm (68X). Almost twins Brighter (2474) primary has a slightly yellowish tinge. Primary in 2470 is more whitish with a slightly purplish secondary.

Colors are subtle,difficult.
 
 

 

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