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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: WRAK]
      #6144255 - 10/18/13 04:31 AM

To point out the obvious: Even the most confident positive reports on Gam Equ result in a puzzle - two observations with 178mm: One with the companion sitting directly on the first ring (or in a gap of the ring), the second with the companion sitting somewhat outside of the first ring (the slight difference in the diameter of the first ring for scopes with and without CO can be considered as too small to be visually relevant here - especially as the ring with CO is the smaller one).
Wilfried
PS: With the companion outside of the first ring with 178mm the resolution should really be not this difficult even with smaller aperture and with ~1.4" separation even the 152mm of Roberto come again into the realm of plausibility


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azure1961p
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Reged: 01/17/09

Loc: USA
Re: Separation Gamma Equ new [Re: WRAK]
      #6144410 - 10/18/13 08:45 AM

I'm looking forward to Cotts results in Florida.


Pete


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David Gray
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Reged: 08/06/12

Loc: Co. Durham UK
Re: Separation Gamma Equ new [Re: WRAK]
      #6146090 - 10/19/13 05:37 AM Attachment (22 downloads)

With another clear night in prospect I delayed posting my Oct 15th good view but passed on a preview (minus graphics) of my impressions via PMs to Wilfried & Fred.

I had pretty much decided to leave it alone as other observing matters were being sidelined. Last night [15th], however, was the first clear for some days, and very good seeing, so I thought I’d give it another go – just to get a look at something…..!!

Again I got the impression of a smokey-orange speck involved/impinging with the first ring: see text accompanying a graphic

To stick my neck out and give my best estimates on this date: mag. 9.5-10; sep: 0.55”-0.65” ; p.a. 200º-220º. If it is that close then it could well be 8.7 but looking fainter/overwhelmed by proximity.

What I contemplate posting is some thoughts on possible variability of the companion. Perhaps not that unusual a variable: an eclipsing one comes to mind; possibly a W UMa type. If this had a period close to 1 day (or even 0.5 day) then it could be that we from our respective locations would be catching it at a particular phase – me conceivably when it is near a minima??! A 0.5 day W UMa EB would fit with a G-K dwarf also.

Looks like some big-scope guys might sort it soon: and if its grossly away from what we are reporting then we have some issues to address – but I can only report what I believe to be seeing!

[Further PM (extract) to Wifried/Fred] I had further good views last night [17th] but after initial near convincing views with a 285mm square aperture mask and in particular when adding a W#15 filter. All I can say as the seeing got to 8/10 I was less persuaded. Then with full aperture it was doubtful to gone in the best moments; with this latter if it was there it was very tight-in; same PA spread though! This was spread over some 3 hours - maybe I caught during a fade.

The square mask gave a very neat Airy: rings subdued similar to the apodizer! Little change evident as regards the disk size: I suppose that the effective resolution would be determined by the diagonal of the square (403mm) which seems borne out by the disk similarity. How the 79mm CO figures with this is outside my knowledge! Further the mask + filter gave me a near pure split of Delta Equ with x535 – clearer than I got it on the 15th (on the graphic to be posted).


I was going to sit a while on this latter report, pending more checks (mask); but a showery regime is setting in here for some days they forecast.....

As long as I keep getting less positive views with improving condtions I have to remain guarded. Maybe the theme of Pete's thread: "Seeing - when less is more?" touches on my experiences?!

David.

Edited by David Gray (10/19/13 06:07 AM)


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David Gray
sage
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Reged: 08/06/12

Loc: Co. Durham UK
Re: Separation Gamma Equ new [Re: David Gray]
      #6146094 - 10/19/13 05:48 AM

Variability of Gamma Equ B: I followed up with these thoughts: elaborated further here

Just as an afterthought on the companion being a W UMa type: presumably we would have two fairly equal stars. This would imply that they were even later than early K – nearer to M perhaps. A stronger ruddy hue then indicated.

I have had some others [family/friends] view my “smokey-orange” (on the graphic) and some are calling it lilac. This brings to mind some old descriptions of Eta Cas B – a red dwarf, as purple, (a lovely red-orange to me). This seems counterintuitive but a shorter step to blue than orange/red. Similarly with red dwarf pair Mu Her BC “cerulean blue”; but again simply red-orange to me Though I feel where less light is involved a seemingly grey comes can be (mis)interpreted as bluish purplish/lilac?.

More thoughts: if Gamma B is a red dwarf pair, do they occasionally flare [YY Gem/Castor C]? As they close to the [intensely magnetic-field of the] primary are they stirred to more activity?!

Time to lie down now…….. or contact Kaler!

The primary is classed as a low-amplitude variable – perhaps hidden in the ‘noise’ is a contribution of B’s possible variability.

It might be worthwhile to see how the inevitable scatter of Gamma B's estimated magnitudes compares with those of similar doubles?

Strange results in the past have sometimes been found to have a cause not anticipated. The 1940/50s colour photometry of Io comes to mind: “ Variable colours”……. “exceptional behaviour of Io” – and now we know why……!!.



Edited by David Gray (10/19/13 06:50 AM)


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Cotts
Just Wondering
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Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: azure1961p]
      #6150310 - 10/21/13 05:51 PM

Quote:

I'm looking forward to Cotts results in Florida.


Pete




Oh, the responsibility........

During my week at Chiefland Gamma Equ will be transiting around 8:30EDT in the evening and be at 70 degrees altitude in the south, high enough to get really good seeing and transparency....

Thanks to Norme and Wilfried I now know that for my TEC 8-incher the following numbers apply, to reasonable accuracy.

Radius to first minimum of diffraction pattern -- 0.62"
Radius to first maximum of diffraction pattern --0.90"
Radius to second minimum ------------------1.36"
Radius to second maximum------------------1.53"

So, if GammaB Equ is anywhere from 1.0" or more it will lie in pretty much dark sky for me, assuming the second ring is virtually invisible, which it should be for a 5th magnitude star....

I will be bringing eyepieces for very high power: 9mm orthoscopic (344x), and my 6mm-3mm Nagler zoom giving 517x, 620x, 775x and 1033x at the click-stops.

And a 1.8x Barlow.....

Dave

Edited by Cotts (10/21/13 05:52 PM)


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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: Cotts]
      #6151127 - 10/22/13 06:08 AM

Dave,
if advertised data and observations of Bill is to be confirmed then you should get a nice diamond ring with the companion sitting on the first ring. If John reported correct then it would be an easy resolution in the second minimum. Can it be this easy?
If David's report reflects reality you will get a negative result but to confirm it you will need another scope.
Wilfried


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Asbytec
Guy in a furry hat
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Reged: 08/08/07

Loc: La Union, PI
Re: Separation Gamma Equ new [Re: Cotts]
      #6151141 - 10/22/13 06:34 AM

It would be interesting to know if you could nab Gamma Equ visually between the rings (or where ever it is) or image it. I think the data above would help us figure out where it is and why it's so hard...and if between the rings makes detection easier. I'm curious to know if the dark space makes detection easier even if the rings nearby are not seen. Something keeps the companion hidden: glare or interference?

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banatop
member


Reged: 05/06/07

Re: Separation Gamma Equ new [Re: WRAK]
      #6151856 - 10/22/13 03:11 PM

Quote:

Dave,
if advertised data and observations of Bill is to be confirmed then you should get a nice diamond ring with the companion sitting on the first ring. If John reported correct then it would be an easy resolution in the second minimum. Can it be this easy?
If David's report reflects reality you will get a negative result but to confirm it you will need another scope.
Wilfried




Actually Wilfried, I said (as quoted by Bill)"The view was almost exactly like the left hand one in the Pdf, which Bill posted on the 27th of September, except that the diffraction ring was visible most of the way round ,save for a break where the companion was (the companion was slightly outside of the diffraction ring). I went back to the star the following day when conditions were the same with an identical result."

The companion was very close to the first diffraction ring and gave a very nice diamond ring effect as drawn by Bill. As I said, my observation was almost identical to Bill's and It wasn't difficult due to the seeing. ( Please note that there is a subtle but real difference between the terms "easy"which I didn't use and "not difficult" which I did.) The reason that I said it was "not difficult" is that the companion was simply there and required no special effort to see it, certainly due to the seeing. Anyway, good luck to Dave and I'm sure, given excellent seeing, he'll succeed. Best, John


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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: banatop]
      #6152993 - 10/23/13 05:30 AM

Quote:

... the companion was slightly outside of the diffraction ring...




John, thanks for clarification - I then misinterpreted your quote above as may be slight but in terms of separation distinctive deviation from Bill's observation of the companion sitting directly on or in a gap of the first diffraction ring.
Wilfried


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azure1961p
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Reged: 01/17/09

Loc: USA
Re: Separation Gamma Equ new [Re: David Gray]
      #6153314 - 10/23/13 10:07 AM

David,

I think you nailed it well when proposing that stars seeming toward a shade of grey can be confused with lilac or blue even though its orange. The lack of a certain or brighter coloring allows it to be more subject to color contrast illusion effects. I actually learned color illusion effects from Alan MacRobert in one of his star hop articles I had at the scope one night . His mentioning a neighboring star to a yellow was lavender and Ive seen the suggestion of that there and elsewhere since. A greyish star that fan seem to go either way in color is subject to that Ive found - particularly when its faint. But it needs yellow to kick it off. On fairness MacRobert wasn't implying lavender stars but merely the effect .

This is a vexing star to be sure .


Pete


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Cotts
Just Wondering
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Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: azure1961p]
      #6153425 - 10/23/13 10:53 AM

I'll have a stab at the colours I see as well. Stars down around 9th mag or fainter pretty much all look pale green-white to me, probably because that's the colour our eyes are most sensitive to....

I will also do a video and lucky imaging too.

While I'm in chiefland I may even look at some other objects.....

Dave


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Cotts
Just Wondering
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Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: Cotts]
      #6165959 - 10/30/13 09:11 AM

Two nights in chiefland and the seeing has not been better than Pickering 6. I've spent some considerable time on it and no hint of a companion at 391x. Higher magnifications are not supported by the seeing. The diffraction rings are moving quite a bit, sometimes gathering on one side of the spurious disc, sometimes flaring into fuzz and sometimes very symmetrical and still ( but never for long enough times to really stare at it...)

I made three videos (varying exposure and ISO) for lucky imaging and will be processing them today.

The dew here is biblical in quantity.....

Dave


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Asbytec
Guy in a furry hat
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Reged: 08/08/07

Loc: La Union, PI
Re: Separation Gamma Equ new [Re: Cotts]
      #6166027 - 10/30/13 09:43 AM

Hurry up, will ya? (In jest )

Thank you for taking the time and effort. Hope you got something.

Are you taking requests? Got a few...


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Cotts
Just Wondering
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Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: Asbytec]
      #6166194 - 10/30/13 11:25 AM

Sure, request away!!

Dave


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Asbytec
Guy in a furry hat
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Reged: 08/08/07

Loc: La Union, PI
Re: Separation Gamma Equ new [Re: Cotts]
      #6166207 - 10/30/13 11:31 AM

BU 9AB, 1 and 13 Del.

Kind of jivin with ya waiting for your results. But, hey..

Saw your diagonal thread, too.


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Cotts
Just Wondering
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Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: Asbytec]
      #6168013 - 10/31/13 09:27 AM

Well, it appears to be a bust, weather-wise. Last night was very hazy until well past 1:30 am. I did try to observe the two Delphinus pairs but the air was very unsteady again, worst of the three nights here.

My 'lucky imaging' results on Gamma Equ showed no hint of a companion star.

Tonight iappears cloudy and Friday night and most of Saturday there will be thundershowers, by all accounts. Thus, I will be leaving friday at noon...

It is nice to be sitting here in shorts and a t-shirt, though...

Dave


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Asbytec
Guy in a furry hat
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Reged: 08/08/07

Loc: La Union, PI
Re: Separation Gamma Equ new [Re: Cotts]
      #6168144 - 10/31/13 10:33 AM

Well, I am sure we all appreciate your attempt. I do. Maybe it's a clue to how difficult these are.

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drollere
Pooh-Bah
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Reged: 02/02/10

Loc: sebastopol, california
Re: Separation Gamma Equ new [Re: fred1871]
      #6176056 - 11/04/13 06:54 PM

Quote:

Note the details I and others gave in discussing the pair in the earlier thread. The separation is now pretty definitely LESS than 1.0".




this makes a useful point. it never hurts to mention the epoch of measurement (or catalog), or at least be aware that the source doesn't give the epoch.

many double stars are "fixed", and most barely change over decades or more, but improved measurements can change the picture. it never hurts to know the epoch.


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