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A doubles list 6" to 0.3" with mag/sep ADDED

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#1 azure1961p

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Posted 30 December 2012 - 11:13 PM

I put this together via SKYSAFARI. This is a re edit of the original as now the magnitudes and seperations are added. Some like the first entry is extreme and impossible for me particularly in winter seeing but others are with in grasp range at least in elongation terms with decent seeing. Still if I keep getting 5 pickering seeing all bets are off on elongated doubles at any sep.

Hope the added info helps clarify.
List: December Doubles

Sigma Orionis 3.79-6.73v, 0.2"
(Double Star in Orion)

Nair al Saif - Iota Ori 2.77-6.88v, 11.4"
(Double Star in Orion)

Meissa - Lambda Ori 3.39-5.29, 4.4"
(Double Star in Orion)

118 Tauri. 5.8-6.5v, 4.8"
(Double Star in Taurus)

c Orionis. 4.59-7.80, 1.5"
(Double Star in Orion)

32 Orionis. 4.23-5.43, 1.3"
(Double Star in Orion)

52 Orionis. 5.3-5.3, 1.3"
(Double Star in Orion)

Delta3 Tauri. 4.3-7.6, 1.4"
(Variable Double Star in Taurus)

HD 27691. 7.11-8.51, 1.2"
(Double Star in Taurus)

HR 1442. 6.2-6.3, 3"
(Double Star in Taurus)

HR 1898. 6.4-8.4, 4.2"
(Double Star in Orion)

HR 1891. 6.26-6.96, 0.4"
(Double Star in Orion)

n1 Orionis. 5.46-6.56, 1.9"
(Double Star in Orion)

Mintaka - Delta Ori 2.23-2.33, 0.3"
(Variable Double Star in Orion)

31 Tauri. 5.69-5.79, 0.7"
(Double Star in Taurus)

HD 54455. 9.56-9.57, 1.5"
(Double Star in Gemini)

HR 2896. 5.34-5.94, 0.7"
(Double Star in Gemini)

HD 58382. 7.19-9.99, 1.1"
(Double Star in Gemini)



Pete

#2 Asbytec

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Posted 31 December 2012 - 04:19 AM

Thanks, Pete, got a few of those under my belt. The toughest were, by far, c Ori and less difficult 31 Tau. The most attractive were 32 and 52 Ori. So far, anyway.

#3 CelestronDaddy

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Posted 31 December 2012 - 10:00 AM

Pete - Thanks for the list! No worries on the particulars, g... :grin: Tony

#4 azure1961p

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Posted 31 December 2012 - 11:37 AM

It's merely a list of fairly easy to challenging doubles overhead right now. I strayed away from the 30" doubles and such though some of these have components far and wide still, but the closer pair within is still fairly tight.

Pete

#5 CelestronDaddy

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Posted 31 December 2012 - 11:57 AM

Pete - I'm looking to get a double star list together for this new years observing too! I just got the 6SE so I'm going to use the list of DS's. I'm looking forward to finding some double star challenges for the new scope and giving it a try when the weather / clouds finally move out, g... Tony

#6 azure1961p

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Posted 31 December 2012 - 05:22 PM

Hi Tony,

It should be good! My C6 did terrific on doubles with nice clean diffraction patterns. Tomorrow I'm going to fill in the other details on the list I made to flesh it out a little more. At least magnitude and separation. You duly have an effective doublestar instrument.

Ill have the the list revamped tomorrow Tony!

Pete

#7 CelestronDaddy

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Posted 31 December 2012 - 05:33 PM

Hi Pete - Excellent and thanks for taking time to put this all together... very nice! Can hardly wait to get out and start checking out some of the DS's on your list :grin: So far I've enjoyed the 6SE but I haven't been able to do much observing since we have had all the cloud cover. I hope it clears out for the weekend... Thanks again... Tony

#8 ziridava

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Posted 01 January 2013 - 11:19 AM

Pete
Thank you for the list,it is very useful.
Here it is already dark (a sort of) ,the sky is clear (a sort of)and I was looking for new targets.
There are other designations for the n Ori and c Ori double stars?
Taurus is a new double star field to me,so I have some hopes.
Here it is very cold,after one-two hours I expect my secondary mirror start fogging.

Because you mentioned wide double stars ,I would like to make a question:
Why there is not a topic on binocular double star observation,please?
Or did I miss it? :rainbow:

Thank you once again,Mircea

#9 azure1961p

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Posted 01 January 2013 - 03:18 PM

Good question . That'd probably be in the binocular forum. If I recall something on the order of 14-15" is the tightest doubles possible with tripod mounted 7x50s. In that range anyway. Edz has always been good about posting binocular doublestar information.

Pete

#10 CelestronDaddy

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Posted 01 January 2013 - 04:29 PM

Pete - Thanks for updating. I've copied and printed your list! Looks like some good challenges :grin: Now if the clouds would only move out,g... Tony

#11 azure1961p

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Posted 01 January 2013 - 10:51 PM

If you can, put a small fan suspended by rubber bands behind the mirror blowing up. The mirror and interior never trul cools too ambient and as a result the dew never forms on my secondary so long as my fans a runnin. Too it'll sharpen your image nicely.

CelestronDad: it'll clear up soon enough. I don't kno if you are new to doubles. If so, generally the 5" doubles are nice low power objects in an seeing conditions almost. The 2-3" doubles are roughly 150x things and 1" or less is 300x or better and a really still sky. Magnitude differences can make even 3" doubles impossible in all but the best seeing or impossible in any conditions if its spread out enough. Try the wide doubles first. If you know all this forgive me please. Again, my 6" Nexstar SE after an hours cool down and even average sky's shows some nice stars. I know yours will too.

Pete

#12 CelestronDaddy

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Posted 02 January 2013 - 12:14 PM

Pete - Thanks! I was very active in observing about 25 years ago and double stars were one of my favorites. I'm a little rusty now but I'm looking forward to getting back up to speed. So any advice I get is appreciated! I just need some clear sky :grin: Tony

#13 ziridava

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Posted 02 January 2013 - 04:52 PM

Pete
Thank you for the tip,I was unaware a fan is helping also on this.
I intend this year to re-build my 8 inch F/6 Dobsonian with a much taller rocker and a solid tube,I will add a fan on that one.

I will check the Binocular forum.Until now my best binocular result on double stars was a separation of 27''.

Last night I saw with my 125mm refelctor two double stars in Taurus ,Sigma 716/5'' separation and 88 Tauri/one minute.
Sky transparency was not very good so I made an experiment delayed since quite a while.
I made observations at about 100x using a Galilean eyepiece on some double/multiple stars in Orion.The results:
-the companion of Rigel was hard to see,lost in the light of the main star,but doable with a bit of effort
-Mintaka and Meissa was clearly split
-the companion of Alnitak was nor split but the two Airy discs of different sizes were visible in an 8 shape
-the greatest surprize was provided by Sigma Ori.One of the companions,a brighter one is at PA=estimated 30 degree,anyway located somewhere in the first quadrant.
I saw a much fainter companion at 200-220 degree ,anyway located in the third quadrant.
The surprize was ,and still is,that the faint companion was seen only with the Galilean ocular and not seen in any other ocular,Plossl,Orthoscopic or Radian.
Next I moved the telescope to Sirius where I saw in the Galilean ocular some dim stars,very close to Sirius ,three at West of Maximus Stella,roughly in a North-South direction,and more-not counted-only at South of Sirius.
I don't remember either to see this dim neighbors of Sirius.

Regards,Mircea

#14 CelestronDaddy

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Posted 02 January 2013 - 08:52 PM

Ziridava - Glad you are able to get out and observe! Good report... We have had nothing but clouds for the last several weeks it seems,g.... Tony

#15 fred1871

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Posted 03 January 2013 - 06:08 PM

Pete, for those of us who don't have SKYSAFARI software, there are some obscurities in your list. In particular, what are the RA and Dec for "c Ori" and "n1 Ori" as these are not designations that appear to be used elsewhere - which means they're unidentifiable without that software.

The various HR and HD numbers can be translated into meaningful designations and from that, positions, via tables available on the web; those two don't have obvious translations.

#16 azure1961p

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Posted 04 January 2013 - 07:37 AM

Ill have a look at Fred.

Pete

#17 rigel58

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Posted 19 January 2013 - 05:58 PM

I have a question, guys. I can't seem to locate "c Orionis". Where is this star or is there another designation? The ONLY thing I can guess at is it is the "c" star of the trapezium. I'd like to try this star tonight, but I can't if I don't know where to look!

Thanks,

John..

#18 Asbytec

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Posted 19 January 2013 - 10:23 PM

Try 42 Ori.

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#19 azure1961p

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Posted 21 January 2013 - 12:44 AM

Pete, for those of us who don't have SKYSAFARI software, there are some obscurities in your list. In particular, what are the RA and Dec for "c Ori" and "n1 Ori" as these are not designations that appear to be used elsewhere - which means they're unidentifiable without that software.

The various HR and HD numbers can be translated into meaningful designations and from that, positions, via tables available on the web; those two don't have obvious translations.


Fred ,

My apologies for the late reply. Here's the clarifications:

42 or C Orionis is 5h36m2.7sc. Ra, -04 49' 55.6" dec

N1 Orionis is actually 33 Orionis .

Sky sees 42 as though it were its neighbor C which would appear to be an error on safaris part lest im reading it wrong.

Pete

#20 fred1871

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Posted 23 January 2013 - 02:38 AM

Thanks for that, Pete.
I think it shows a problem that occurs with some software packages for astro use, where the guys creating them know more about programming than astronomy, so we get strange designations creeping in, as well as catalogs that aren't the usual ones for primary identifications. Because a lot of objects have multiple identifiers this can lead to a lot of extra searching through catalogs. And in the case of strange designations, as with "c Ori", it creates puzzles unless one has the same software. Good reason therefore to give RA and Dec except when using standard names - in the case of double stars, typically those used by the WDS catalog, or Greek letters etc that are standard usage, and are common to atlases that aren't idiosyncratic (Norton's, various Tirion atlases, etc.....)

#21 azure1961p

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Posted 25 January 2013 - 07:31 AM

Well Safari is good in that it gives at least several designations. Still and oddly enough when I typed in one of the names you questioned that they had listed it would recognize it in the search engine . It sais 33Orionis is N1 but it won't allow it to be looked up as such.

Pete






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