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Jabbah – cool double-double in Scorpius

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#1 dotnet

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Posted 02 August 2014 - 07:29 AM

I had some success tonight with Jabbah (Nu Scorpii) using my 6" Mak, despite rather ordinary seeing. It is an attractive pair of doubles even though not very colourful. At this time of the year it cruises at about 60 degrees altitude during prime observing time at my place. Here are my notes:

"What a double-double! AB pair split at 360x (space between components little more than space between diffraction rings). Slightly uneven pair, component pointing towards CD pair is somewhat smaller. Both components look white, angle about 30 degrees off the axes AB-CD. CD pair much easier although fainter, clear split at 150x, best at 210x. More uneven and more yellow than AB pair."

Sky Safari lists the pairs' separation as 1.3" (AB) and 2.2" or 2.3" or 2.4" (CD). Does anyone have better data?

Cheers
Steffen.

#2 pepit

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Posted 02 August 2014 - 07:43 AM

Nu Scorpii is a very nice double-double - a nice pair in a small telescope and a nice 4 star system in a medium sized instrument.

According to Turn left at Orion, the separation of the A/B pair is 1.3", while C/D is 2.3".

#3 fred1871

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Posted 02 August 2014 - 08:32 AM

A pity about the title of this thread - makes it sound like something from Star Wars. Most of us know this combo as Nu Scorpii - saves memorising the 400-odd individual star names, and gives immediate reference to which constellation and which star without intermediate reference. It's not like referring to Sirius or Vega.

#4 jrbarnett

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Posted 02 August 2014 - 04:01 PM

Half the fun of *amateur* astronomy is mastering the sky-lore rather than the science, IMO.

- Jim
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#5 fred1871

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Posted 02 August 2014 - 07:26 PM

Jim, for you, maybe. I've never found memorising long lists of obscure names adds anything. And I have a solid interest in astro history and sky lore; but referring to objects by obscure names doesn't strike me as helpful or add anything to enjoyment. YMMV.

 

If someone is following name trails, they may find it interesting, because their interest is in the names. But when reporting an observation, using an obscure name only slows down a lot of us for discovering what object is being referred to. So it's a distraction from the (presumed) purpose of the note.

 

Regarding Nu Sco, it's a fine double-double that's had quite a bit of discussion here recently. The closer (and brighter) pair are fairly tough unless you have good seeing, and that's going to be less frequent for northern hemisphere observers (low in the sky). In good conditions, I find all four stars neatly seen with my 140mm refractor and middling magnification, say 160x-240x - how well separated do you want the AB pair? I have seen AB barely separated with a very good 4-inch, but a bit more aperture helps. CD can be made out as a neat pair with an 80mm refractor.


Edited by fred1871, 04 August 2014 - 01:07 AM.


#6 Sarkikos

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Posted 06 August 2014 - 02:04 PM

Half the fun of *amateur* astronomy is mastering the sky-lore rather than the science, IMO.

- Jim

+1 :waytogo:

 

Mike



#7 Sarkikos

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Posted 06 August 2014 - 02:05 PM

 

Half the fun of *amateur* astronomy is mastering the sky-lore rather than the science, IMO.

- Jim

+1 :waytogo: ... but the other half is the science.

 

Mike

 



#8 CelestronDaddy

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Posted 06 August 2014 - 05:17 PM

Steffen - good post ... btw what EP's were you using?



#9 dotnet

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Posted 06 August 2014 - 11:31 PM

 btw what EP's were you using?

 

Hi Tony, a Vixen LV 5mm for 360x and a Pentax XF 8.5mm for 210x. Yep, I've got that big gap in my magnification range, that I'm desperate to close. My plan is for a 3-6 zoom and some nice 7mm...

 

Cheers

Steffen.



#10 CelestronDaddy

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Posted 07 August 2014 - 07:02 AM

Hi Steffen - those are nice EP's! I usually use orthos on doubles (6, 7, and 12.5mm Circle T/Circle V). I sometimes use an ES 11mm 82 deg. I've never used a zoom before on doubles but that might be nice though. Thanks for the info on the EP's you use ... Clear Skies ...

#11 Love Cowboy

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Posted 09 August 2014 - 12:55 PM

ARRGHH

 

You mean to tell me there's a FOURTH star in this system?   Dadgum it.  I was working on the AL double star list last night... it of course only lists the wide separation between the two pairs, as it's geared toward being relatively easy.  I was surprised and feeling accomplished to find the CD pair (which my notes list as BC), and I never noticed B at all... grr.  Time to re-do this one. 



#12 dotnet

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Posted 09 August 2014 - 09:48 PM

According to Jim Kaler it's even a quintuple system, with A actually being Aa-Ab. However, their separation is supposedly 0.0003", so nothing visual observers need to concern themselves with ;)

 

Cheers

Steffen.



#13 pepit

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Posted 10 August 2014 - 11:00 AM

According to Jim Kaler it's even a quintuple system, with A actually being Aa-Ab. However, their separation is supposedly 0.0003", so nothing visual observers need to concern themselves with ;)

 

Cheers

Steffen.

Probably someone in the refractor forum has already seen them :D .



#14 payner

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Posted 10 August 2014 - 01:55 PM

"Probably someone in the refractor forum has already seen them :D ."

 

 

I'm still chucking at this ... so funny and would not be surprised!

 

Best,
Randy








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