edosaurusrex
sage
Reged: 01/30/07
Posts: 371
Loc: Ft Worth, TX
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Next time you're in the neighborhood of "the" double-double in Lyra (eps1-2) go 3deg NE of gamma Lyr (Sulafat) and find Struve2470/2474. Both were split with a 4.5in at 36X and in the same field of view. No acid test here for optics but a nice low power double-double.
Struve 2470 6.6m 8.6m 13 sec
Struve 2474 6.5m 8.6m 16 sec
They are 11 arc min apart from each other.
Ed K
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asteroid7
Post Laureate
Reged: 10/19/04
Posts: 4273
Loc: CT
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Here's a sketch of this fine-looking double-double.
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Clear Nights "Make My Day"
4.5" f/7 APM (TMB) APO Refractor CG5 GoTo with Orion extension tube
8" Celestron CPC (two)
Eyepieces:
40mm Pentax; 24mm Tele Vue Panoptic, 18mm Tele Vue Radian, 18mm HD Ortho, 15mm Celestron Omini,14mm Pentax,10mm Tele Vue Radian, 7mm,5mm & 3.5mm Nagler; 7.4mm Tele Vue Plossl.
2.5 Tele Vue Powermate
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 18806
Loc: Cumberland, R I , USA42N71.4W
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HMMM. considering the distance between the two pairs, I would expect this sketck would show the close components almost on top of the primaries?
This is a favorite binocular double for 15x, 16x or greater.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Dave Mitsky
Postmaster
Reged: 04/08/02
Posts: 24600
Loc: PA, USA, Planet Earth
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The Other Double Double is one of my top ten favorites.
Dave Mitsky
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Chance favors the prepared mind.
A man is a small thing, and the night is very large and full of wonders.
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userlain
super member
Reged: 08/10/06
Posts: 165
Loc: Montana
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Are these true doubles, or just optical doubles? Also, does anyone have RA/Dec coordinates for these? My astronomy software, KStars, doesn't have Struve objects.
Regards,
Jacob
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Jake
Orion StarMax 127 on Celestron CG-5GT
Celestron 7Ah PowerTank
Orion XT8 Classic
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edosaurusrex
sage
Reged: 01/30/07
Posts: 371
Loc: Ft Worth, TX
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I have the center of the 2470/2474 pair at J2000
RA 19h 09.0m
Decl N34d 31m
Edited by edosaurusrex (09/09/07 04:26 PM)
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asteroid7
Post Laureate
Reged: 10/19/04
Posts: 4273
Loc: CT
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HMM. This sketch was only the second day that I started
sketching back in 2005. I looked at my old notes and it
appears that the stars should be around 50% closer but not
on top of one another. Will have to look at this one next time I go out under the stars. Magnifying 67x for this sketch.
Rich
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Clear Nights "Make My Day"
4.5" f/7 APM (TMB) APO Refractor CG5 GoTo with Orion extension tube
8" Celestron CPC (two)
Eyepieces:
40mm Pentax; 24mm Tele Vue Panoptic, 18mm Tele Vue Radian, 18mm HD Ortho, 15mm Celestron Omini,14mm Pentax,10mm Tele Vue Radian, 7mm,5mm & 3.5mm Nagler; 7.4mm Tele Vue Plossl.
2.5 Tele Vue Powermate
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Herchel
super member
Reged: 08/09/07
Posts: 106
Loc: Toronto
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I remember finding the artical about the double doubles double a few years ago, a very beautiful site but I recall them being alot closer together
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4inch F15 Antares refractor vixen spec ,Celestron 11 inch Newt ,Orion 127 Mak ,Antares 4.7 Refractor very fast, Kendricks dew system first productions still going ,sold the rest of the scopes , and have a small Observatory http://photos1.blogger.com/blogger/7364/791/1600/0033.jpg 
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 18806
Loc: Cumberland, R I , USA42N71.4W
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It was mentioned correctly above, the pairs are separated by about 11 arcmin. However, the close secondary components are 13" and 16". Therefore the Pairs are spread apart 40x wider than the close separations of each secondary, not 2x to 3x. That's why it's referred to as the Double Double's double.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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RLTYS
Post Laureate
Reged: 12/18/04
Posts: 4267
Loc: New York (Long Island)
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Ed
In my 10" refl, at 76x, 2474 and 2470 make an almost identical double-double. Stf 2474, Primary Very Pale Yellow. Secondary Yellowish. Stf 2470, Primary White. Secondary Yellowish.
Clear Skies
Rich (RLTYS)
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10" F4.8 Refl.
4" F5 Refr. (Genesis)
3" F4 Celestron FirstScope
50mm F12 Refr. (Tasco #6TE-5)
12x63 and 10x50 Binoculars.
"I want to do more then just look."
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edosaurusrex
sage
Reged: 01/30/07
Posts: 371
Loc: Ft Worth, TX
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Rich,
Your description is spot on. I just hope folks here (especially newbies) that have never seen it take the time to track 'em down and see for themselves.
Ed
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proud uncle
Carpal Tunnel
Reged: 01/22/07
Posts: 1688
Loc: Central Texas
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Ed, thanks for the info. I had seen that in my S&T Pocket Sky Atlas, and planned to look for it my next time out. It's nice to have some background info. Is 2470/2474 a binary system, or just optical? I assume 2470 and 2474 are each true binary systems?
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Kenneth
Nikon 10x50 binocular
Zhumell 10" Dobsonian (f/5)
eyepieces: 32mm (2" WA), 20mm, 12.5mm, 9mm (EWA), 6mm (TMB/BO Planetary), and 2X Barlow
Wratten filters: #21, 25A, 47, 56, 80A, and ND13
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edosaurusrex
sage
Reged: 01/30/07
Posts: 371
Loc: Ft Worth, TX
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Hi Kenneth,
According to Sissy Hass they are both optical.
Ed K
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proud uncle
Carpal Tunnel
Reged: 01/22/07
Posts: 1688
Loc: Central Texas
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Viewed these for the first time last night! I easily had a clean separation at 39x, but upped my power to 62x for a little more separation. Very nice! My view was very similar to Rich's sketch, except each of the secondaries were closer.
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Kenneth
Nikon 10x50 binocular
Zhumell 10" Dobsonian (f/5)
eyepieces: 32mm (2" WA), 20mm, 12.5mm, 9mm (EWA), 6mm (TMB/BO Planetary), and 2X Barlow
Wratten filters: #21, 25A, 47, 56, 80A, and ND13
Edited by proud uncle (09/13/07 03:41 PM)
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ABC
sage
Reged: 10/22/06
Posts: 422
Loc: Heidelberg, Germany
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Last night, I had a clean separation with my new 70mm f/10 Achromat at 22x. I did not notice this multiple star system before. A very nice suggestion! Thanks.
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Kind regards, Christian
Meade 178 ED
Meade 152 ED
Intes Micro Alter M500
Bresser 70/700 Achromat
CGE
EQ-6
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asteroid7
Post Laureate
Reged: 10/19/04
Posts: 4273
Loc: CT
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Revised sketch
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Clear Nights "Make My Day"
4.5" f/7 APM (TMB) APO Refractor CG5 GoTo with Orion extension tube
8" Celestron CPC (two)
Eyepieces:
40mm Pentax; 24mm Tele Vue Panoptic, 18mm Tele Vue Radian, 18mm HD Ortho, 15mm Celestron Omini,14mm Pentax,10mm Tele Vue Radian, 7mm,5mm & 3.5mm Nagler; 7.4mm Tele Vue Plossl.
2.5 Tele Vue Powermate
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userlain
super member
Reged: 08/10/06
Posts: 165
Loc: Montana
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I split these tonight, but it was hazy so I couldn't distinguish colour. It turns out that the two sets don't orbit each other, whereas the sets are very far apart. One of the sets isn't actually a double at all but rather an optical double.
They are still beautiful though!
Jacob
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Jake
Orion StarMax 127 on Celestron CG-5GT
Celestron 7Ah PowerTank
Orion XT8 Classic
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CESDewar
GorillAstronomer
Reged: 01/16/05
Posts: 2085
Loc: Blue Ridge, GA, USA
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Quote:
Revised sketch
Probably being a bit picky here  but the PA's in this revised sketch seem a bit too different to me - I see the PA's as being quite close to each other. SN shows them at 262° and 268° which seems to match my visual observation - the original sketch I think shows the PA's more accurately...
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SaberScorpX
Post Laureate
Reged: 01/12/05
Posts: 4224
Loc: illinois, usa
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Another look and the DSS plate:
http://tinyurl.com/6xqvmn
Stephen Saber
PAC/Astronomical League
www.astronomyblogs.com/member/saberscorpx
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http://saberdoesthestars.wordpress.com/
Saber Does The Stars (Vol 2: the Index Catalog)
http://www.caldwellcatalogue.blogspot.com/
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JohanK
super member
Reged: 05/21/07
Posts: 171
Loc: Ghent, Belgium
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Quote:
No acid test here for optics but a nice low power double-double.
Never heard of these two doubles before. Had a look at them yesterday.
Very nice target(s), indeed.
Thanks for letting us know about it.
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Johan
Orion XT10, Takahashi TSA-102
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