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2 mysterious designations

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#1 flt158

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Posted 07 December 2019 - 07:49 AM

Hello everyone. 

I'm still wading my way through certain parts of Cassiopeia. 

Using www.stelledoppie.it I have come across and observed 2 double star designations in this wonderful constellation. 

Neither double star is a true binary. 

But here are the mysterious designations. 

1. CTT.

 

2. ARY.

 

Minimal magnifications are needed to split both. 

Even less than 40x which I used. 

 

CTT 3 and ARY 35 are both relatively bright, but I cannot find who their discoverers are. 

 

Clear skies from Aubrey. 


Edited by flt158, 07 December 2019 - 10:52 AM.


#2 beggarly

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Posted 07 December 2019 - 09:22 AM

http://www.astro.gsu...s/wdsnewref.txt

 

ARY: Argyle, R.W.

CTT: Courtot, J.-F

 

https://www.webbdeep...ction-circulars


Edited by beggarly, 07 December 2019 - 09:35 AM.

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#3 flt158

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Posted 07 December 2019 - 10:56 AM

Excellent, Beggarly!

2 mysteries solved. 

 

And a big thank you for providing us the links. 

 

Kindest regards from Aubrey. 



#4 The Ardent

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Posted 07 December 2019 - 01:13 PM

One reason to like sky safari, has a lot of the obscure double names. 

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#5 flt158

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Posted 07 December 2019 - 01:44 PM

I do find it quite confounding as to why these 2 double stars which are completely optical are getting onto any double star list. 

ARY 35 has magnitudes 8.2 and 7.6. The separation is a whopping 115.4". The PA is 133 degrees. 

CTT 3 has magnitudes 7.8 and 8.3. The separation is a bit tighter at 88.1". The PA is 88 degrees. 

Okay - it is advantageous to find them both. 

After all they did guide me to other nice doubles that are in the area. 

However it might be the case they are good for owners of small telescopes or binoculars. 

 

Kind regards to everyone, 

 

Aubrey. 


Edited by flt158, 07 December 2019 - 06:51 PM.


#6 ssmith

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Posted 07 December 2019 - 05:20 PM

Something isn't making sense to me in regards to the ARY designation.

 

All the discovery dates for the ARY systems are from the late 1800's to the early 1900's.

All the publications attributed to R.W. Argyle (ARY) are from the 1970's to the present.

 

What's wrong with this picture?


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#7 ssmith

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Posted 07 December 2019 - 05:48 PM

After a bit more searching I may be able to answer my own question.

 

It appears that measures were made using "pre-discovery" photographic plates such as from the Cartes du Ceil Sky Atlas which was begun in the late 1800's.

 

So in these cases the "First Date" in the WDS doesn't necessarily reflect the date that the system was first cataloged but the earliest date that measures could be established.


Edited by ssmith, 07 December 2019 - 05:49 PM.

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#8 flt158

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Posted 07 December 2019 - 06:53 PM

You sure keep wonderful historical records, Steve. 

Please do keep up the good work. 

 

Kind regards, 

 

Aubrey. 



#9 WRAK

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Posted 09 December 2019 - 02:13 PM

http://www.astro.gsu...s/wdsnewref.txt

List of all WDS discoverer and reference codes


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#10 flt158

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Posted 09 December 2019 - 05:23 PM

No more mysterious designations from me, Wilfried!

 

Thank you for helping us all out with that wondrous link. 

 

Best regards, 

 

Aubrey. 



#11 fred1871

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Posted 09 December 2019 - 08:38 PM

That site is the mirror version of what was usually available on the USNO site for WDS and related matters, currently down for extended-period site maintenance, as Wilfried had indicated previously.

 

Using the WDS mirror I was pleased to see that the full WDS is still being updated in content, as per the usual practice. So, not merely a mirror of the past state, which makes it more useful for those who want their information from the horse's mouth as it were. Location for the full WDS is http://www.astro.gsu.edu/wds/ (a reminder).


Edited by fred1871, 10 December 2019 - 02:01 AM.

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#12 c2m2t

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Posted 14 December 2019 - 05:35 PM

"I do find it quite confounding as to why these 2 double stars which are completely optical are getting onto any double star list."

 

Hi Aubrey!

In response to your comment above, the majority of double star catalogues from the past started out as records of observations. Over time and repeated observations, certain systems were proved to be actually gravitationally bound. I believe the majority of systems included in the WDS prior to 2000 are in fact optical pairs. The inclusion of a system in the WDS is not an indication of it being a binary pair but rather a pair/multiple that has been found, observed and recorded so that future observers could compare to eventually prove or disprove their binary nature. New entries into the WDS are restricted to actual binary systems because we have the technological tools, space observatories, that detect the proper  motion in real time. To summarize, the WDS is a record of all the recorded observations since the first observer pointed a telescope at the night sky and recorded the positional data of stars in close proximity. It is shortly after these early observational records that the laws of gravity were discovered and the new discipline of measuring close proximity stars provided the earliest values for stellar mass. For the next 200 years up until the mid 1800's, double star observations was the primary activity of observatories as they started to give size and scale to the known universe.

 

This is a very simplistic history of double stars and the part they played in the field of astronomy, but it should provide a clearer understanding of how the WDS came to be. The USNO, United States Naval Observatory, took on the responsibility of bringing all these scattered catalogues into one larger catalogue which became the WDS.

 

Cheers,

Chris Thuemen

Pembroke, Ontario.


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#13 flt158

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Posted 14 December 2019 - 06:38 PM

Hello, Chris. 

Thank you very much for entering in on this issue. 

Astronomical history is a very fascinating subject to delve into.

Clearly for many it has been a real learning curve - myself included. 

As a result of finding these somewhat mysterious designations, they both have enabled me to offer my other report which is called "8 double stars and 2 triples in Cassiopeia" here on Cloudy Nights. 

 

Clear skies, 

 

Aubrey. 



#14 fred1871

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Posted 16 December 2019 - 02:01 AM

"I do find it quite confounding as to why these 2 double stars which are completely optical are getting onto any double star list."

 

Hi Aubrey!

In response to your comment above, the majority of double star catalogues from the past started out as records of observations. Over time and repeated observations, certain systems were proved to be actually gravitationally bound. I believe the majority of systems included in the WDS prior to 2000 are in fact optical pairs. The inclusion of a system in the WDS is not an indication of it being a binary pair but rather a pair/multiple that has been found, observed and recorded so that future observers could compare to eventually prove or disprove their binary nature. New entries into the WDS are restricted to actual binary systems because we have the technological tools, space observatories, that detect the proper  motion in real time. To summarize, the WDS is a record of all the recorded observations since the first observer pointed a telescope at the night sky and recorded the positional data of stars in close proximity. It is shortly after these early observational records that the laws of gravity were discovered and the new discipline of measuring close proximity stars provided the earliest values for stellar mass. For the next 200 years up until the mid 1800's, double star observations was the primary activity of observatories as they started to give size and scale to the known universe.

 

This is a very simplistic history of double stars and the part they played in the field of astronomy, but it should provide a clearer understanding of how the WDS came to be. The USNO, United States Naval Observatory, took on the responsibility of bringing all these scattered catalogues into one larger catalogue which became the WDS.

 

Cheers,

Chris Thuemen

Pembroke, Ontario.

Chris, a good summary, but the puzzle I think is that two current observers got optical pairs listed, not too far in the past, and with no suggestion of cpm which one would expect to be a good starting point. Other very wide pairs listed in the WDS in recent decades appear to be cpm pairs, sometimes with the benefit of credible similarity of parallax. So they could well be very wide binaries, or perhaps co-travelling in space.

 

So I understand Aubrey's puzzlement. Long gone are the days you refer to of adding pairs that have a merely plausible appearance, or the habit of cataloguing every lesser star roughly in the field near a bright one - which certainly increased the number of optical doubles very quickly. 
 


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#15 The Ardent

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Posted 16 December 2019 - 11:07 AM

Is it possible they were doing some other kind of survey and noticed these pairs?
Or as an easily located marker for some other discovery?
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#16 c2m2t

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Posted 16 December 2019 - 11:48 AM

Hi Fred1871!

If that is indeed the case, I suspect there must be a good reason to have added these pairs. Are you able to provide the "WDS identifiers" for these two systems? I believe I have read comments regarding these occurrences but would be hard pressed to put my fingers on them at this point in time. It is certainly the exception and not the norm to have non-physical pairs added now. 

 

Cheers, Chris.


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#17 ssmith

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Posted 16 December 2019 - 04:32 PM

Chris, a good summary, but the puzzle I think is that two current observers got optical pairs listed, not too far in the past, and with no suggestion of cpm which one would expect to be a good starting point.


And what is more surprising is that one of them - R. W. Argyle (Bob Argyle) - literally wrote the book “Observing and Measuring Visual Double Stars”.

Edited by ssmith, 16 December 2019 - 05:52 PM.

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#18 flt158

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Posted 16 December 2019 - 05:35 PM

Sometimes astronomy does make us laugh, Steve! lol.gif

 

And I do thank you all for your correspondence. 

 

Kindest regards from Aubrey. 



#19 fred1871

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Posted 16 December 2019 - 08:20 PM

Hmmm... memory lapse by me. Although CTT 1 has PM numbers strongly suggesting optical, ARY 8 has PM numbers suggesting possible connection. 

 

00003+5651CTT   1      1906 2015   14  90  93  49.4  46.1  8.59 11.39 A2        +031+008 +001-004 +56 3129  U   000020.41+565111.4

 

00108+5846ARY   8AB    1910 2015   19 100 100  39.4  39.1  8.13  8.63 B3IV      +007-004 +006-004 +57   18      001037.25+584453.6
00108+5846ARY   8AC    1910 2015   15  43  43 104.4 104.3  8.13  8.29 B7V       +007-004 +006-002 +57   22      001037.25+584453.6

 

Rather surprising that earlier observers who collected wide doubles didn't list the components of ARY 8: it was much the same in 1910 (presumably Carte du Ciel plates measure) as in 2015. Visually, it should make an easy broad triple for small scopes. This kind of wide object is what might be expected to be in the catalogue lists of John Herschel and James South from their work discovering doubles using small telescopes (3 3/4-inch and 5-inch) in the early 1820s.




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