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Cotts
Just Wondering
*****

Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: WRAK]
      #6117402 - 10/04/13 02:41 PM

At Okie Tex we have had astonishingly good viewing weather. Six nights in a row of crystal clear skies, lows in the 50's and high 40's. Seeing from below average to above average. I tried Gamma Equ every night at least twice, early and late, with my 16" Zambuto f/5 dob with powers up to 800x.

At no time was I given any hint of a companion. There were times that the seeing was good enough to briefly show the inner diffraction pattern of the star, indicating seeing approaching 0.25". No companion.

If, as bill says, the delta magnitude is 4 and the separation is 1.1" or less, then we have an excruciatingly difficult pair here.

Dave


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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ new [Re: Cotts]
      #6117545 - 10/04/13 04:07 PM

Just to clarify, I'm not claiming the secondary is dimmer than advertised. I'm claiming it is dimmer than the primary... (I see the prime as white-cream white, secondary as a tiny sparkle, white-blueish, the darker shade being on the side away from the primary). Because of the difference in hue, the illusion of magnitude difference is amplified. The diffraction ring arcs on my illustration were as bright or brighter (seemingly) than the companion. But the secondary sat there plain and still - never wavered.

I am interested and somewhat astonished to read Dave's entry above. Wow! I trust those results with that kind of aperture and seeing. And I know his logs. I certainly don't have any idea why this object is so tough. I have a request in to one of the Haas contributors in FL, using a 14.5" dob if he will give it a shot.

It occurs to me, that I have more than once seen a double star better using less aperture, not more. Seems counterintuitive, but the more light gathering ability, the more glare in some cases. 90 Her is another on the Haas list that is far more challenging than the data suggest.

I don't know what else to say about it. My first two attempts last year were throw away, because I was using 100 mm. I got my first resolution on my second attempt with 178 mm. This year, I found it surprisingly easy - as soon as I hit x300; there it was. I viewed it on and off for an hour and twenty. The star never left the field and the secondary never wavered. Time permitting, I will make another observation, record everything as carefully as I can and attempt a color illustration for reference. Good luck to all. It is tough. Has Mark (Nucleophile) weighed in on this one yet this season? He got it last year, too. I'm also interested to see if Roberto can grab it with 152 mm and good sky.


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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ *DELETED* new [Re: Cotts]
      #6117553 - 10/04/13 04:07 PM

Post deleted by Bill Boublitz

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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117569 - 10/04/13 04:21 PM

Here's an idea; Has anyone thought of an occulting bar? I don't have one, but I bet that would do it!

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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117575 - 10/04/13 04:24 PM

I deleted the above post because it was accidentally a duplicate of my first entry above...

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Cotts
Just Wondering
*****

Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117606 - 10/04/13 04:44 PM

Bill, you need to delete 7 more 'copies' of your post...

As for the topic at hand, aperture may indeed be my foe. We'll soon see as I will be trying this pair from the Chiefland Fall Star Party in much better Florida seeing conditions.

Dave


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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ new [Re: Cotts]
      #6117845 - 10/04/13 07:16 PM

Damn... What happened? Sorry gang. It wasn't me, I swear.

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Cotts
Just Wondering
*****

Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117896 - 10/04/13 07:58 PM

An old idea for viewing the moons of Mars: Take a dark blue, violet or green filter, 1.25". Remove the glass from the cell, cut the filter in half with a glass cutter, replace the half filter in the cell and place in the eyepiece focal plane.

Many modern eyepieces have the focal plane between the lenses so older designs like orthos, plossls, RKE's, Kellners etc. are the eyepieces of choice...

the trick is to get the edge of the glass exactly at the focal plane of the eyepiece.......

the advantage of this is that you can still see the primary but it is greatly reduced. Just rotate the eyepiece to the correct PA and the secondary may be more easily visible.....

I'm going to try to make one of these out of an old 6mm ortho that I have in my junk box.....

Dave


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117961 - 10/04/13 08:40 PM

Bill, your success with Kui 97 in Cygnus is of interest. What magnification, what seeing conditions, and how easy/difficult was it?

Reason for asking is that I'm seeing odd variations in what can be achieved in unequal doubles observing. There are some examples of pairs that, on the numbers, should be more difficult than others, but prove less difficult. I've had the same experience myself - one night I had two doubles near each other, on the numbers X is tougher than Y (slightly); but X was easier/more obvious than Y. Yet the photometry in WDS seemed fine, and the measures history of both seemed fine. I remain puzzled - same observer, same telescope, one observed straight after the other (then a back and forth check).

Kui 97, on the numbers, is tougher than 42 Orionis. But from your comment ("it was beautiful") it sounds as if you found it easier. Both doubles, Kui 97 and 42 Ori, have delta-m of 2.9; but Kui 97 is closer, 0.8" compared to (probably) 1.0" for 42 Ori (1.1" listed a while ago, but slowly closing).

Now it might be that Kui 97 is easier because it sits in the first dark interspace of the diffraction pattern - which is ~0.8" for 7-inch aperture. Where 42 Ori for that aperture is roughly on the first bright diffraction ring.

In the case of 90 Her, the first diffraction ring should sit on the secondary at ~125mm aperture. So, noting the list of successes on that one, on the Haas project website, I see 3 positive reports for 100mm, only 1 each for 120mm and 130mm, and 4 for 150mm. Which suggests the possibility that the diffraction ring has an effect here; more reports would confirm or dis-confirm this. Of course, it might just mean fewer observers have 120-130mm telescopes.

So, some variations can be regarded as consistent with the effect of diffraction rings on faint companion visibility. But others don't seem to fit that model. I've used 90 Her and 42 Ori as cases where diffraction does seem to have explanatory value.

In the case of Gamma Equulei we have a problem insofar as attempting to evaluate observations doesn't have a current measure to work from. We don't definitely know whether the pair is similar to 2002, closer, or has started widening again. David Gray's experiments in orbit tracing suggest but can't prove that the pair is likely closer than 2002. So all we can do for now is gather observing reports, and eventually, when we have a new measure, evaluate from there.

Meanwhile, Cotts' attempts and David Gray's are suggestive of a VERY difficult double.


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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ new [Re: fred1871]
      #6118497 - 10/05/13 04:26 AM

HDS2446 in Her 0.9" +4.62/8.53mag seems to be a good candidate for checking resolution of a double with comparable advertised data to Gam Equ. If the data for Gam Equ is correct it should be doable with 200mm with reasonable seeing and with 180mm with very good seeing - although with a delta-m of 4 any CO size might already be counter productive. Large aperture being a foe for resolution? Don't know - only with inadequate seeing - the most difficult doubles were always discovered with very large apertures.
Wilfried


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Asbytec
Guy in a furry hat
*****

Reged: 08/08/07

Loc: La Union, PI
Re: Separation Gamma Equ new [Re: WRAK]
      #6118725 - 10/05/13 10:02 AM

I gave Gamma Equ a good hour tonight. No go at any mag from 310 to 390x. NELM about 4.5, seeing 7/10. Field stars down to 12th mag were visible, but the 9th mag companion was not. Not even a hint.

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azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Separation Gamma Equ new [Re: Asbytec]
      #6118954 - 10/05/13 12:25 PM

Lol I don't even want to attempt this one.

Pete


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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ new [Re: azure1961p]
      #6119297 - 10/05/13 04:41 PM

Pete, this one would be a perfect target for your 8" Newton.
Wilfried


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azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Separation Gamma Equ new [Re: WRAK]
      #6119719 - 10/05/13 10:05 PM

Its funny, the other time I saw it in my finder when lining up on Delta and I just shrugged and thought "nahhhh too difficult". Ill give it a wing but if a guy can see it as fringey as Dave had at 16" - halving that would seem to be asking for disappointment though Im pleased to see Bills effort. I might try it but Id have a hard time reconciling it against a large cassegrain. I'm not trying to over inflate the difference but if its fringey to begin with - halving the resolution would seem damning.

Lol but Ill try Wil.

Pete


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ new [Re: azure1961p]
      #6120994 - 10/06/13 05:22 PM

First clear night in weeks for me - in fact a whole month. Seeing started good with NEML of 4.5 but deteriorated by the time I got to 5 Equ. Result is that I could not split it at 450x with my 6" Apo.
Earlier in the session I tried Kui 97 as per Bill's post earlier in the thread. Got a rod-like structure with confirmed PA.


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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ new [Re: R Botero]
      #6121650 - 10/07/13 01:44 AM

I sympathize, Roberto. If I go back to the fourth post in this thread, you have already seen it. I hope you get the chance to observe again, not that I need this thing resolved, but I think you've already seen it.

I was out tonight as well, viewing Kui 97 with 100 mm to ascertain the field and be certain I had focused on the correct object the other night. I made a drawing of the field and find I did in fact, align correctly on Kui 97. Not to hold out, but I want another solid resolution before I star blabbing about it.... perhaps on a new thread. (Hint: white/sky blue kissing pair.... ?)


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Karl Fabian
super member
*****

Reged: 11/02/11

Loc: Illinois
Re: Separation Gamma Equ new [Re: Asbytec]
      #6122288 - 10/07/13 12:07 PM

Quote:

I gave Gamma Equ a good hour tonight. No go at any mag from 310 to 390x. NELM about 4.5, seeing 7/10. Field stars down to 12th mag were visible, but the 9th mag companion was not. Not even a hint.




The Clear Sky Clock says good seeing tonight. If the Clock is correct, going to give Gamma EQL a try with my 8inch SCT. At 1" with a 4 magnitude difference it would seem to be beyond reach, but the WDS 2002 measures may very well be wrong after 11 years. In any case negative results are just as useful to the project as confirmation. Not only does the project seek to discover at what point is a target resolved but also when it is not.
I am doing most of my observing with a 90mm achro since they are looking for more reports with apertures 100mm and below. However this Gamma thing has me interested so I'll give it a try.
Most recent confirmation with 90mm was 23Aquilae (5.3-8.3, 3.2"). Secondary held steady at 123X with averted vision in my light polluted suburban back yard. Interestingly this target did not take high mag well. At 200x secondary not visible despite 1/2 hour scrutiny with perfectly defined airy disk with faint first ring in Pickering 8 seeing. Dropped to 123X and secondary popped up like magic. Visibility of faint secondaries with some targets can sometimes be improved if the airy disk has it's light more concentrated into a smaller area. An airy disk acts like any extended object by having it's light spread out more at higher magnification. Sometimes magnification is a balancing act.


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Asbytec
Guy in a furry hat
*****

Reged: 08/08/07

Loc: La Union, PI
Re: Separation Gamma Equ new [Re: Karl Fabian]
      #6122315 - 10/07/13 12:17 PM

Karl, great point on dimmer Airy discs at higher power. Forgot about that while bouncing between Chi Aql and Gamma Equ. Good luck with your Gamma Equ attempt. I hope you report success.

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azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Separation Gamma Equ [Re: Karl Fabian]
      #6123355 - 10/07/13 06:50 PM

Quote:

Quote:

. In any case negative results are just as useful to the project as confirmation. Not only does the project seek to discover at what point is a target resolved but also when it is not.
.




EXACTLY! A negative result is still positive in the interest of collecting statistical data.

Pete


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Astrodj
professor emeritus
*****

Reged: 08/24/11

Loc: Missouri
Re: Separation Gamma Equ [Re: azure1961p]
      #6123995 - 10/08/13 01:30 AM

I took another crack at Gamma Equ tonight. The seeing started out at Pickering 3-4 at 9pm local. I didn't bother with it at this point. Later, at about 11pm the seeing had improved steadily to Pickering 6 by my reckoning. I had just finished with Bu67 so I moved to Gamma Equ to see what I could see.

So as not to lead anyone on, I did not succeed.

I was using the 10" dob on an EQ platform. Magnifications used were 217x, 300x, 363x, 454X, and 600x. Time spent observing was in excess of 45 minutes. Gamma was well past zenith, but the seeing was much improved from earlier. I carefully examined the proper position angle for the companion and could not see anything that would suggest a sighting at any magnification.

After warming up on Bu67 I had hopes of better results from my first attempt, but I must say it looked about the same as last time. The seeing was a steadier than before, but no hint of the companion.

A tough nut to crack.


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