Author Topic: Nice binocular double star  (Read 446 times)

Prana

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Nice binocular double star
« on: March 29, 2017, 10:38:32 AM »
Was looking through the good old Night Sky Observers Guide last night, curious about double stars in Cygnus - I am out before dawn these days and Cygnus is up high then.

I came across 61 Cygni, aka Struve 2758.  Its a wide double, 30.3" separation, which makes it good for binoculars.  Its the color I'm really interested in seeing - here's the description from the book:


"61 Cygni, a wide, easy separated double of two orange K-type dwarfs, is only 11.2 light years distant, the twelfth nearest star or star pair to the Solar System.  The two stars orbit each other in a period of 650 years, and will achieve maximum separation, 34", bout 2100 A.D.  The components have luminosities of only 8% and 4% of the Sun's.  Their color is probably at its best in binoculars, with which both stars are a stunning chrome orange-red.

4-6" Scopes - 75x: An easy target for small telescopes, 61 Cygni is a wide pair of bright orange stars."

Its easy to find, just off Tau Cygni behind the western wing.  Anyone seen this double?

mccarthymark

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Re: Nice binocular double star
« Reply #1 on: March 29, 2017, 11:00:15 AM »
June 2014 from my backyard in 12.5-inch: "Both bright orange, near equal, but A is slightly brighter.  Faint bluish optical companion to A with AV."

AKA Piazzi's Flying Star for it's high proper motion; one of the first to be measured by parallax method to try to determine its distance; a lot of observing history on this one.

Check out Stelle Doppie; 18 stars visible in the system!?  Is it a double or a cluster?  http://stelledoppie.goaction.it/index2.php?iddoppia=93063
Mark

Prana

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Re: Nice binocular double star
« Reply #2 on: March 29, 2017, 11:10:01 AM »
Check out Stelle Doppie; 18 stars visible in the system!?  Is it a double or a cluster?  http://stelledoppie.goaction.it/index2.php?iddoppia=93063

Holy moley!  That's impressive!  And a good question....

DDK

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Re: Nice binocular double star
« Reply #3 on: March 29, 2017, 05:10:09 PM »
61 Cygni was the very first star to have its distance measured by humans. Friedrich Bessel used parallax and a lot of work to find the distance of that pair, in 1838. Very cool science. And Bessel way opened up our idea of how big space is; >100 trillion kilometers is a hike.

And it is a beautiful double, I've looked at it a bunch of times, partly to think about it being just about 11 lightyears away (11.4 - Bessel was close at 10.3). Shows up pretty in a 9x50 finder.

Had no idea there were 18 stars bunched up there.
« Last Edit: March 29, 2017, 11:56:20 PM by DDK »
TAC - astro anarchy at work <*>