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Kruger 60

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#1 azure1961p

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Posted 28 July 2014 - 10:50 PM

Here's a double that first caught my attention coming across it in Burnhams Celestial Handbook. As some know its 13.5 light years away, has an orbital period of just under 45 years and - its B component is a Flare Star - capable of erratic magnitude increases in times as short as 8 minutes with a two fold increase in brightness.

I've checked it from time to time ever hoping to see either a detectable shift in position over the years as well as the luck of catching a flare. Anyone ever monitor this one for either?

Pete

#2 dotnet

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Posted 29 July 2014 - 09:55 AM

Sounds intriguing, but alas, at almost +58 degrees Dec this is firmly out of my reach.

Cheers
Steffen.

#3 Edward E

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Posted 29 July 2014 - 10:42 AM

I was wonder the same thing. I cannot recall anyone posting an observation of this double. Like you I read about this star in Burnham's C.H. It's on my list of doubles in Cyg to observe when it clears up.

#4 azure1961p

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Posted 29 July 2014 - 11:04 AM

Its easy enough to see with the 8 as you'd imagine / and wide at that. I've never hung with it long enough to catch an outbreak - and apparently its all over in under ten minutes. Here's one where leaving a cam run for an hour at a time at high gain could pay off.


Pete

#5 EJN

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Posted 29 July 2014 - 11:25 AM

Here's a double that first caught my attention coming across it in Burnhams Celestial Handbook. As some know its 13.5 light years away, has an orbital period of just under 45 years and - its B component is a Flare Star - capable of erratic magnitude increases in times as short as 8 minutes with a two fold increase in brightness.

I've checked it from time to time ever hoping to see either a detectable shift in position over the years as well as the luck of catching a flare. Anyone ever monitor this one for either?

Pete


I have looked at it in my 8". There is a photo of the B component during a flare in
an old book by Fred Hoyle, Frontiers of Astronomy.

What is really apparent is that if you compare the photo in Burnham's to where it is
now, it has noticeably moved since then due proper motion.

#6 Cotts

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Posted 29 July 2014 - 12:53 PM

Easy? wide? I don't think so.....

The components are 9.93 and 11.41 mags at a separation of only 1.4".

This would be a fairly challenging split for an 8-inch. I have tried with my 16" Teeter and, although I did see both components it was tough work!

I will be trying out a new double star imaging set-up this weekend with my 8" MakCass and Backyard Eos. I will make KR 60 one of my prime targets for imaging....

Watch this space for further details....

Dave

#7 drollere

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Posted 29 July 2014 - 04:16 PM

well, for starters ... this is what happens when you rely on burnham.

cotts is right about the WDS configuration. most of the large number of "components" attributed to this system are faint (13 to 16 mag) stars that were probably catalogued as reference points for the micrometer measurement of proper motion. here's a "finder chart":

Posted Image

#8 David Gray

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Posted 29 July 2014 - 04:40 PM

Not that I have any axe to grind about Burnham’s Handbooks one way or the other; and not that we really need to refer to them these days for such data.

However as there is an orbit diagram on page 599 it is a matter of simple arithmetic to add the period to an appropriate year: in that case 1970+44.46 corresponds to how we see it now………..

I often applied such – years ago before computers came along: simple enough – good enough - for general purpose.

DG

#9 azure1961p

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Posted 29 July 2014 - 05:59 PM

The months Ive given this a look were the warmer (better seeing) and more over from nice dark country sky's. both seperation and detection at 200x was fairly straight forward. "Wide" perhaps isn't applicable but in 7 Pickering or better under good dark sky's it rather lays there. The fainter magnitudes also make the diffraction rings quite a but more subdued than if this was a magnitude 6-8.5 pair.

At anyrate I look forward to your work David.

Pete
Ps: It'd make a nice little animate too of successive images.

#10 azure1961p

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Posted 29 July 2014 - 06:37 PM

Incidentally for anyone taking interest here STF1321 is another flare double - late giant stage. Seperation is much wider than K60's 1.4" and its in Ursa Major.

It'd be an interesting project to form a list if these kinds of objects. I might do that.

Pete

#11 Edward E

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Posted 30 July 2014 - 10:12 AM

What program did you use to make that image in your post drollere? That is very slick.

#12 drollere

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Posted 30 July 2014 - 06:20 PM

that's just a plotting tool in MS Excel, "StarPlotter.xlsx", you can download from my site (linked in .sig). the star icons are "hand painted" to show the magnitude data.

#13 Daniel Mounsey

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Posted 30 July 2014 - 09:05 PM

Here's a double that first caught my attention coming across it in Burnhams Celestial Handbook. As some know its 13.5 light years away, has an orbital period of just under 45 years and - its B component is a Flare Star - capable of erratic magnitude increases in times as short as 8 minutes with a two fold increase in brightness.

I've checked it from time to time ever hoping to see either a detectable shift in position over the years as well as the luck of catching a flare. Anyone ever monitor this one for either?

Pete


Love this post. I wish more people observed fascinating targets like this and thought about what's going on so they'd appreciate it more. The universe comes alive in full color with observations like this wonderful example here. This is what observing is all about.

#14 Edward E

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Posted 31 July 2014 - 09:57 PM

Here is a simulated view of Kruger 60 as viewed in my 152mm Refractor f8 with a 9mm Ortho eyepiece on a night of excellent seeing.

The program used to do this simulator is a JAVA applet from Princeton University and is found at this web site: Double Star Sim You will have to put the web site into the JAVA security exception file for the JAVA script to load up if using Win7 or set the security slide bar to "low" when using this app. Start>Control Panel>Programs>click on JAVA>click on security tab>use slide at top of click on click on "edit site list" box>close>restart browser.

It is a nice application and with a little tweaking of the settings it will give life like renderings.

Attached Files



#15 azure1961p

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Posted 31 July 2014 - 11:51 PM

Dan,

I agree astronomy is best when it has a sense if discovery and exploration about it. Thanks for the kind words.

Ed, that looks about right! I checked the last time I observe K60 and this very change apparent double was infact at least double the seperation it is now!!!! Hence the "easy" description I gave it. Gosh I can't believe its been that many yeArs, they've moved so much!!!

At anyrate - a very nice sim however I saw no color in this pair with my 8 anyway.

Nice presentation.

Pete

#16 Edward E

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Posted 01 August 2014 - 10:26 AM

Dan,
At anyrate - a very nice sim however I saw no color in this pair with my 8 anyway.
Pete


I have not field check Kruger 60 with the 152mm scope yet so it's no surprise the color is off. This app uses the B-V color index for the color approximation and over saturates the color of most stars but there is an setting to adjust that issue.

#17 Perseus_m45

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Posted 02 August 2014 - 09:43 AM

Not that I have any axe to grind about Burnham’s Handbooks one way or the other; and not that we really need to refer to them these days for such data.

However as there is an orbit diagram on page 599 it is a matter of simple arithmetic to add the period to an appropriate year: in that case 1970+44.46 corresponds to how we see it now………..

I often applied such – years ago before computers came along: simple enough – good enough - for general purpose.

DG


Bruce, I would like to commend you for all that art work in your Gallery of Multiple Stars . I use it all of the time.
mike h

#18 azure1961p

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Posted 02 August 2014 - 07:44 PM

I've done some investigative work into doubles with flare components and the list is regrettably short. Excluding binaries with extraudinary delta mags and objects flaring in invisible wavelengths and again flare stars only part of a double or multiple system and its a very exclusive club in our neck of the Milkyway. There's plenty in the heavens by themselves or with invisible partners but alas Kruger 60's are a very rarefied lot from our vantage point.

If anyone has others to add part of a visible binary system without need of Keck Id be glad to hear of it. For now its two or three pairs - maybe.
Pete

#19 3c_273

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Posted 05 August 2014 - 03:37 PM

My two observations:

 

The first one uses data from a 2009 WDS:

 

Telescope: C-8, Observatory: Little Tycho, Date: 2012 Sep 9, Time: 21:51:54
 A difficult pair due to it's faintness. An elongated blob with averted vision.
 WDS data: 9.93 - 10.53mv, M3.5, 62° pa, 135.9", 2009.

 

Last night's uses more recent WDS data.  Not how little the pairs have moved!

 

Telescope: C-8, Observatory: Little Tycho, Date: 2014 Aug 5, Time: 3:21:38
 A difficult pair, owing to the faintness of the secondary. With direct, foveal
 vision, both components vanish, but are bright with averted vision in
 tonight's hazy but Pickering 8-9 skies. WDS data: 9.93 - 10.53mv, M3.5, 62° pa,
 136.8", 2012.
 



#20 Cotts

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Posted 06 August 2014 - 09:49 PM

Tom, you have posted the KR 60 AC data.   The actual binary star in question is KR 60 AB, WDS 22280+5742, mags 9.93 and 11.41, sep 1.4", PA 326deg, 2013 data.   The WDS lists no less than 22 other components for KR 60 A but only KR 60 B shares the proper motion of A, all of the rest of the components are merely field stars .

 

KR 60 A proper motion is -806, -399 (milliarcsec per century) KR 60 B is -713, -321.  The slight difference in the values is due to their mutual orbital motion.  ALL the other components have proper motions two orders of magnitude smaller, all like 002 mas/century which indicates that they are at least 100x further away than the AB pair.

 

Dave



#21 3c_273

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Posted 07 August 2014 - 02:32 PM

Dave,

 

  Quite right, and thanks for noticing it and posting.

 

   Night Assistant merrily grabs the first occurance in the WDS it finds and declares that to be the pair, and I wasn't taking this into account when my post went out.

 

   I'll have to tweak Night Assistant to get it to show how many pairs are associated with a given discoverer name and number.








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