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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6108715 - 09/30/13 06:29 AM

Quote:

... I leave you and your friend to your mutual admiration society. You guys are a riot!




Come on Bill, relax a bit. You did a great job observing Gam Equ and I take your report as serious positive even if I made more or less funny remarks concerning magic (I still can not understand how it is possible to resolve a companion sitting in the first ring being fainter than the ring but I will investigate this topic anyway) and duration of observation.
I apologize if this offended you, was not my intention.
Wilfried


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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]
      #6109154 - 09/30/13 12:02 PM Attachment (27 downloads)

I have been following this thread with interest these past months, with the 415mm (16.3"),f/16, Dall-Kirkham Cass: 19% CO and decided to give the star some scrutiny in recent weeks.

What came out of it I find quite perplexing: several times it was “Yes!!!” then back came the uncertainties. There was usually more certainty with the apodizer applied; and one near-certainty with the 6” off-axis mask; but this ‘companion’ seemed relatively too bright. The attachment summarises most of my impressions.

In addition to what is shown there I can detail a Gamma Equ observation/session on Sept. 28 in very good and improving conditions. Keeping on it for over an hour (in spells!); initially sweeping it up in twilight. At first the impressions were as in the attachment. However as the seeing got better doubts with the companion increased. In the end I applied x665 (non-binoviewer) and still had a very good Airy with well defined rings. But no sign at all of star B! I was starting to wonder if I had strayed onto 6 Equ but no – anyhow its marked blueness would have been the giveaway.

One old trick, which I have tried before successfully (10” Newt.), is to slightly tilt the primary mirror to throw the rings away from where a faint companion might be. Not wanting to disturb the D-K’s collimation I removed the barrel from the 10mm Ortho (Zeiss) I was using; and with a bit of Blue Tack achieved the right tilt to get the same result – and absolutely no companion evident! I’ve not tried this eyepiece-method before so it awaits more clear nights to check it out.

I have seen some mention of the comes being variable and I note that Burnham’s Handbook gives it as a fainter magnitude of 11 as opposed to 8.7, which might indicate an M dwarf but if it is a flare star it must be one of very unlikely vigour!! I have spent hours on occasion with YZ CMi and got a measly, uncertain, 0.3 mag. ‘flare’! Kaler suggests G9 – K0 for Gamma Equ B. which seems to accord with my impressions of light orange at times.

Later in the night I applied the same technique to 85 Peg (0.52” 317º) and got a more definite glimpse (some uncertainty) of the companion than with all my efforts on Gamma Equ. But, as I say, more checking in prospect.

Regards,
David.

Edited by David Gray (09/30/13 03:50 PM)


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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: David Gray]
      #6109259 - 09/30/13 01:09 PM

Excellent report, David. I'm itching to try this one. Your description of "over performing" success brings it home for me - fluctuating between "yes" and uncertainty. You're one time near certainty with a 6" mask is enough to motivate me to take on the challenge. Plus, the observation is one of those that fall into the realm of interesting.

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Astrodj
professor emeritus
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Reged: 08/24/11

Loc: Missouri
Re: Separation Gamma Equ new [Re: David Gray]
      #6109304 - 09/30/13 01:40 PM

I too have kept following this thread with interest. Last night was my first attempt at observing Gamma Equ.

My results were negative on AB, some details follow.

ZLM= 5.5
Transparency= 9 of 10
Seeing= 5, occasionally 6 of 10
10" f/4.7 Nwt, CO 25%
Equatorial platform
Magnifications= 182x, 300x, 364x, 600x
Eyepieces used= 6.6mm Cave Orthostar, 4mm Nihon Seiko Ortho, 2x 3 element Barlow

The 12.5 mag AC companion was easily seen. WDS shows a P.A. of 359. I estimated the P.A. of AC at 005 while at the scope and looked it up later. I used that as a reference for where to concentrate my search for AB. Diffraction rings were breaking up into points that shifted in and out from the primary. In occasional moments of better seeing the rings steadied enough to look like two diffraction rings, albeit briefly.

I had several impressions of a star point near the first diffraction ring that must ultimately be attributed to seeing artifacts as they were at a P.A. of between 25 and 45 degrees. Nothing was seen at the correct position angle that would suggest a 9th mag star.

I will try again, of course...


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Cotts
Just Wondering
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Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ new [Re: Astrodj]
      #6109363 - 09/30/13 02:28 PM

Can't find it for two nights at Okie tex. 16" Zambuto f/5, 19% central obstruction.

Will keep trying.

Advice from a mod:
If you haven't seen it and you haven't tried, don't post.
If you haven't seen it but have tried, don't tell someone else they couldn't have seen it ( by hinting or direct comment)
If you have seen it, post your results dispassionately.

Dave


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David Gray
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Reged: 08/06/12

Loc: Co. Durham UK
Re: Separation Gamma Equ new [Re: Asbytec]
      #6109485 - 09/30/13 03:39 PM

Thanks Norme,

Actually I thought this one was going to be a walk in the park! If I did get the companion then I suspect it nearer mag. 10 than 9.

I was a little hasty with the graphic which I had started, and left, some weeks back and have amended a couple of things for correctness.

Cheers,
David.


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fred1871
professor emeritus


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: David Gray]
      #6109970 - 09/30/13 08:33 PM

David, a very useful report on your observing efforts on this difficult object. It's certainly more of a problem than most of us expected it to be!

Considering magnitudes again, if the secondary star is dimmer than mag 8.7 then the pair becomes more difficult; and the 19th - to early 20th century observers did usually assign a magnitude around 10 or 11 to it. Brighter than that starts with van den Bos in 1958, using the Yerkes 40-inch refractor. The pair was easier at that time than later, it had begun closing but was still reasonably wide - he got a measure of 1.94". Worley in 1988 (26-inch refractor) suggested a delta-m of only 3.3 (mags) - surprisingly bright. Hipparcos and Tycho put the delta-m at 4.25 and 4.0 respectively (1991 for both). Roberts in 2002 has delta-m 3.82, but that's in an R band (red light). If as Kaler suggests the companion is type G9-K0, the companion can be expected to be brighter in R than in V, and thereby reduce the delta-m as the primary is less red (type A9V).

Burnham's Handbook appears to have used the 19th century estimates of brightness for the secondary.

So it's still an open question of whether the secondary is variable; but if it were usually fainter than mag 8.7, we'd have an even more difficult double, so that doesn't help for telescopes of moderate size.

Your "messing around with ellipses" diagram is interesting - I'd suggest the larger ellipse, while possible, is unlikely; and Kaler's suggestion of ~250 year period would be similar to the smaller ellipse. You've plotted the 1994 measure, which shows how far out of trend it is (the briefly-reversing binary ). The curve does suggest a pair continuing to close. Now if only we had a 2013 measure to confirm, or dis-confirm, that.

Your note about "eye estimates for the position" of the secondary also is a fit for an orbit continuing to close, and for a more rapid change and decrease in the PA; consistent with the diagram. So those observers with suitable telescopes should be checking for the possibility of a companion with noticeably smaller PA than previously, 220-250 as per your eye estimates; as well as very close, in the 0.6"-0.8" range. As the first diffraction ring with your 16.3-inch will be near 0.5", that's consistent with your drawing A.

So it's possible, but not certain, as you acknowledge, that you might have seen the secondary star.

Your observation in good conditions of 85 Pegasi is a useful check on what's possible. The delta-m for that pair is similar to Gamma Equ - 85 Peg has WDS mags of 5.83 and 8.9, so delta-m ~3.1, and the very good orbit for 85 Peg means there's no significant uncertainty in the separation you quote (0.52").

My final thought is that I envy you with a 16.3-inch DK with small secondary; seems to me it's a pretty much ideal planetary/double star telescope.


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azure1961p
Postmaster
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Reged: 01/17/09

Loc: USA
Re: Separation Gamma Equ new [Re: Cotts]
      #6110074 - 09/30/13 09:27 PM

Quote:


If you haven't seen it but have tried, don't tell someone else they couldn't have seen it ( by hinting or direct comment)

Dave




Well said.

Fred you might be interested to see the .17" double split Dave illustrated in another forum.

Pete

Edited by azure1961p (09/30/13 09:47 PM)


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fred1871
professor emeritus


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: azure1961p]
      #6110236 - 09/30/13 10:44 PM

Pete, yes, I did see that, showing a 0.17" pair as elongated, in the thread about "Detail on Ceres?" - an excellent result, and entirely believable given the telescope etc; consistent with Christopher Taylor's efforts, with RG Aitken's comments, etc. But I won't personally be attempting A 2145 with the (much) lesser telescopes I currently have.

Regarding telling other people - there's an implication involved, even if you're merely discussing the limits of physical optics, that someone could not have seen what they claim. An error has crept in. No dishonesty involved; incompetence isn't needed, we all sometimes get false positives. So if someone claims to see a double as a double at 0.5" with, say, a 63mm Zeiss Telementor (a very fine little telescope), the only response, whether or not you say it, is that it's beyond the bounds of possibility for that aperture.

That's because it goes beyond the physics, and no matter how keen the eye, it can't see what the optics can't show. As I've said before, that's quite different from differences in colour perception; and quite different from seeing fainter, where visual acuity can make a big difference.

In the case of Gamma Equ, we can say that the 1994 measure is anomalous, an "outlier" in Brian Mason's diplomatic language, plainly some kind of error is there; and David Gray's plotting of the measures shows that well enough. Is it a typo? - a copying mistake? - an error with the measuring system? - we can't tell, and the astronomer who made the 1994 measure is very competent and very experienced. But everyone has the occasional error, and later they might be able to identify how it happened.

Meanwhile, looking at what David Gray can see with his 'scope, I've got the same feeling Jonckheere had when using his first serious telescope for double stars - it was near 9-inch aperture, and he did not think it big enough - so his next telescope was a 14-inch, much more satisfactory. Sometimes the only way forward is more aperture, given optics of suitable quality and design.

Edited by fred1871 (10/01/13 08:25 PM)


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azure1961p
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Reged: 01/17/09

Loc: USA
Re: Separation Gamma Equ new [Re: fred1871]
      #6110276 - 09/30/13 11:07 PM

There's interesting things in the errors that come through poor measures. Its a little frustrating on one hand but it adds a wild card element that can leave a lot in the lap of the observer. At anyrate I for one had no idea this double was this terribly difficult. Discovery is still alive here and that's a good thing.

Pete


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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: David Gray]
      #6110553 - 10/01/13 03:44 AM

Quote:

... one near-certainty with the 6” off-axis mask; but this ‘companion’ seemed relatively too bright...




David, do I understand it right that your other observations made this a false positive?

Regarding your observations with full aperture - impressive report. With an aperture of 415mm only seeing should be the limiting factor for resolving Gam Equ if the advertised data would be at least nearly correct - so may be seeing is the reason for the remaining uncertainities. It also shows that even evidently positive observations have to be double checked. From the specs of your DK scope would result a separation of about 0.6" - even with this small separation Gam Equ should be rather easy resolved with 415mm if +4.7/8.7mag are correct. I think you would come to the limit of your scope with 0.6" +4.7/~10mag.
But all this means that I will not only have to forget about my 140mm refractor but also my coming 200mm DK not to speak about the C925 with it's counter productive CO of nearly 0.4 - or I might have to put a mighty spell on it.

Remains quite interesting.
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: WRAK]
      #6110731 - 10/01/13 08:30 AM

Quote:

...do I understand it right that your other observations made this a false positive?



Or a positive maybe.


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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: WRAK]
      #6111338 - 10/01/13 02:19 PM

Quote:

Quote:

... one near-certainty with the 6” off-axis mask; but this ‘companion’ seemed relatively too bright...




David, do I understand it right that your other observations made this a false positive?




As it stands I guess I would say that. But as far as the 6" off-ax. goes it is based on very few tries. I am modifying the mask for quicker attaching/removing as it is too tight a fit; supposed to 'drop' in the end and also needs a central knob or such.

I am only hoping my recent good seeing has not ended. They have just harvested and ploughed the adjacent wheat-field and I have suspected, over the years, that this seems to affect my local seeing for some weeks. Perhaps coincidence or simple supposition I don't know.

I will persevere regardless with Gamma Equ. I am hoping to check out similar doubles to further evaluate things. I will be trawling Sky Map of course but suggestions welcome - preferably those following the meridian as I have houses to the s'west and seeing is less reliable that direction.

This is an intriguing challenge and thank you all for your comments and insights on my report. Hopefully further offerings - inc. other doubles in due course!

Cheers,
David.


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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: David Gray]
      #6111556 - 10/01/13 04:46 PM

Some suggestions:
ID Name RA Dec Separation Magnitude Magnitude2 Constellation
WDS02132+4030 MET14 02:13:13 +40:30:28 0,7 5,68 9,88 And
WDS04564-0510 HDS641 04:56:24 -05:10:17 0,6 5,49 9,64 Eri
WDS05397+2554 OCC231 05:39:44 +25:53:50 0,6 5,18 9,46 Tau
WDS06042-0643 HDS826 06:04:13 -06:42:32 0,6 5,24 9,45 Mon
WDS07123-4030 HDS1001 07:12:16 -40:29:56 0,7 5,31 9,4 Pup
WDS07187-2457 TOK42 07:18:42 -24:57:16 0,9 5,33 9,7 CMa
WDS08116+3227 CRJ2 08:11:39 +32:27:26 0,6 5,09 10 Cnc
WDS08319+5037 CRJ3 08:31:55 +50:37:00 0,9 5,96 10,07 Lyn
WDS08345-0044 MET53 08:34:32 -00:43:34 1 5,44 10,28 Hya
WDS13239+5456 PSF1 13:25:14 +54:59:17 1 4,01 8 UMa
WDS16278-0822 RST3949 16:27:48 -08:22:18 0,8 4,71 8,83 Oph
WDS17177+3717 HDS2446 17:17:40 +37:17:29 0,9 4,62 8,53 Her
WDS20176-1230 WZ15 20:17:39 -12:30:30 0,8 4,44 8,6 Cap
WDS23300+5833 STT496 23:30:02 +58:32:56 0,8 4,87 9,3 Cas
WDS23587-0333 BU730 23:58:40 -03:33:21 0,8 4,9 8,9 Psc
Wilfried


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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: WRAK]
      #6112515 - 10/02/13 06:22 AM

Many thanks for these Wilfried – might get to look at some of them in a couple of days if the clear-sky forecasts hold……!

With regard to gamma Equ I have to say if I had included this in my occasional, more casual, double star forays then on the basis of my more-convinced ‘sightings’ I would have probably moved on to the next object quite satisfied as to the companion detected ! The need for more experience my tackling this type of double seems indicated…..

You may right with Bill's observation and I hope he continues to tackle gamma - I've not laid the matter to rest that's pretty sure!

David.

Edited by David Gray (10/02/13 08:50 AM)


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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: David Gray]
      #6112542 - 10/02/13 07:08 AM

David, regarding aperture mask - with a CO this small you could also use regular aperture masks down to 10" aperture without getting CO larger 0.28 and still expect performance of an 8" refractor. Should be enough to resolve Gam Equ if the WDS data is near reality but with less influence of seeing.

Meanwhile I wonder if Bill has seen a ghost (some kind of reflection of the primary within his optics) as the observation report includes two irregular aspects: Fainter companion seen in interruption of brighter diffraction ring and defocus producing ring around the secondary and not the primary as to be expected.
Wilfried


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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: WRAK]
      #6112628 - 10/02/13 08:45 AM

Wilfried, I had something in mind a while back for on-axis masks - could even simulate certain sized SCTs (CO-wise) this way. But your 10"-cum-8" 'refractor idea has not occurred to me but will certainly give it a go.

I did allude to this somewhere on CN; possibly on Norme's Multi-mask thread: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/6017180/page...
There is a fair bit of detail re. my efforts with masks/apodizers and touching on doubles.

Bills observation: could be some seeing effect - I have been getting some apparently anomalous too-bright 'companions' throughout my investigations. I've not proved much - hope he continues to tackle the star.

David.

Edited by David Gray (10/02/13 09:01 AM)


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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ new [Re: David Gray]
      #6114531 - 10/03/13 03:15 AM

Tried it last night with 140mm and seeing Pickering ~6 but it was hopeless as the diffraction pattern was not stable enough to be able to identify any faint spot between disk and first ring with such a small aperture. Think Gam Equ meanwhile rather impossible with 140mm, only perfect seeing could may be do the trick.
Did not see much sense to try it also with the C925 with the given seeing.
Wilfried


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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ [Re: WRAK]
      #6116553 - 10/04/13 04:03 AM

The primary is estimated magnitude 4.7. The secondary is magnitude (estimated) 8.7. It IS dimmer... (forgive the vernacular).

1. I am certain I don't have enough experience.
2. I am certain my observations are spurious.
3. I am certain my mirror is "pinched."
4. I am certain I made an arithmetic error typing in the P.A. at 4 am in the morning, last year.
5. The lords of the double star section have asked for repeatability and I have given it to them. I remain in waiting...
6. I am relaxed; I just resolved Kui 97 (Cygnus). It was beautiful! (Same spurious observation, same inexperienced observer, same pinched mirror... it was beautiful!)

You guys have fun doing what ever you're doing....

I leave you to your work.


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WRAK
scholastic sledgehammer


Reged: 02/18/12

Re: Separation Gamma Equ [Re: Bill Boublitz]
      #6117107 - 10/04/13 11:53 AM

Quote:

... I just resolved Kui 97 ...



Congratulation, certainly a challenge for 178mm, excellent acuity of vision.
Should be a tad easier than Gam Equ with given WDS data and a lot easier if the companion of Gam Equ IS dimmer than advertised as you say.
Wilfried


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