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3 Doubles near Achird

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#1 flt158

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Posted 25 December 2019 - 08:41 AM

Happy Christmas to everyone here on the Double Star observing forum!

 

On Christmas Eve night I set up my William Optics 158 mm f/7 apochromatic refractor and my William Optics 70 mm small apo on a Berlebach Planet altazimuth mount with mirror diagonals fitted to both scopes. 

From about 9 pm I was delighted to see Cassiopeia had come down from my zenith. It was time for real action. Sky conditions were extremely good. 

 

As some of you know I have been working through the magnificent "W" constellation for quite a while now. 

I had observed NQ Cassiopeiae for the first time. 

But before I got to it I was also observing some faint doubles on the way. 

 

1. Stf 16 was my first port of call. I simply thought I would have no problems with this double. Stelle Doppie says that the primary is white (A3) but no spectral class was given for the secondary. 

For the record the magnitudes are: A = 7.7. B = 8.8. Sep: 5.9". PA = 41 degrees. I was very happy to see a very slim dark gap at 40X through a 2" eyepiece. It was very nice. 

A is white alright. But what about B?

As I increased through 112X, 140X and 167X I was seeing orange or red for the secondary. 

When I came indoors at a later stage, I checked Sissy Haas and states A is white; but B is blue white!

I then checked Burnham, and he just says both stars share a common proper motion with an A3 spectrum. Nothing for B. 

Guide 9.1 DVD agrees with Sissy Haas. So it is a real personal conundrum. 

My next 5 nights are due to be overcast. 

But I will have to observe it again at some stage. It's vital I do so. 

Maybe I will embarrassed by what I find. 

I notice Stf 16 has not been discussed on Cloudy Nights in the past.   

 

2. In the same fov as NQ Cas, ES 42 is positioned as one of the stars shaped like a cross - an asterism for sure. 

A = 8.4. B = 9.4. Sep = 7.1". PA = 207 degrees. Split at 112X. ES stands for the Reverend Espin. 

 

3. HDS 44 is even easier. It's below NQ Cas. 

A = 9.0. B = 10.3. Sep = 12.3". PA = 38 degrees.

 

Comments and questions are always welcome. 

 

Kind regards from Aubrey. 

 


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#2 c2m2t

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Posted 25 December 2019 - 09:26 AM

Hi Aubrey!

We here in eastern Ontario are experiencing conditions similar to you...cloud !!! For the next week we will have temps 15 to 20 degrees above normal. I saw your post while enjoying a quiet Christmas morning. We celebrated Christmas last weekend given my son's familly(2 grand children) are now with his in-laws in south central Quebec. We head off this afternoon to stay over with my daughter before the Christmas reunion on my wifes side on Boxing Day...60+. Therefore, the opportunity to peruse CN for more interesting discussion.

 

How fortuitous, I just happen to be working in Casseopeia... imaging, processing and preparing narratives for my "groups.io" double star imaging group. I have imaged all 3 systems. What is rather interesting is that ES 42 is buried in a wonderful little asterism that resembles the constellation that we find it in...non other than the "M or W", depending of your perspective, of our celestial queen Casseopeia. Hopefully you will have another opportunity to observe this trio and I would greatly appreciate your observation of whether or not my images are representative of what you are seeing at the eyepiece. Keep in mind that these are correct image(naked eye)...you may have to flip the image to imitate the orientation you have at your EP. 

 

If you would like me to send you the files...not sure what a download from this forum will provide...just let me know.

 

Merry Christmas to all!!

 

Cheers, Chris.

Attached Thumbnails

  • STF 16-6285-ns-ID.jpg
  • ES 42-6320-ns-ID.jpg

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#3 c2m2t

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Posted 25 December 2019 - 09:27 AM

Here is the third image of HDS 44. Not enough room on the previous reply

Attached Thumbnails

  • HDS 44-6305-ns-ID.jpg

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#4 The Ardent

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Posted 25 December 2019 - 04:31 PM

Aubrey 

Please examine the highly curious and  interesting asterism HD 222794 located 45’ from Tau Cas. 
 

 

Attached Thumbnails

  • CF559083-C835-4808-8822-E84336812B96.jpeg

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#5 flt158

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Posted 25 December 2019 - 07:35 PM

Hello, Chris and Ray.

I thank you both very much for your responses.  

Thank you for taking the time to communicate with me. 

 

Chris: I too was very busy today on Christmas Day. 

My wife and I were entertaining an Englishman (who is now an Irishman thanks to Brexit), a married couple from Brazil and 2 Malaysian students. 

 

The next clear night I get I am going to have observe Stf 16 again as a top priority. 

I should have seen it the same way as your image; except that my east is to the right and my north is to the left. (I have mirror diagonals fitted). Your colours are what I should have seen. 

Which means, of course, minimal colours at all: white and blue -white.  

It's amazing you took the time to image ES 42 and HDS 44. 

I was very happy to observe them both. 

The only reason I bothered to have a look at them was because both doubles were so close to the carbon star NQ Cassiopeiae. 

 

Ray (The Ardent): Your asterism is wow!

It is very near to where I am observing. 

On stelledoppie.it the whole asterism is called ENG 88 as you do state above. 

It is a 6 star asterism and it is most certainly is one that requires a good observation. 

Thank you very much for drawing my attention to it. 

I have found all 6 stars on Guide 9.1 DVD. 

 

Clear skies from Aubrey. 



#6 fred1871

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Posted 25 December 2019 - 08:30 PM

Hmmm.... don't think I've come across 'Achird' as a star name before, so I looked it up, and found Eta Cassiopeia was meant. Neither edition of the Cambridge Double Star Atlas has the name on the charts - it does show the names for other bright stars in Cas.

 

Checked Wikipedia (quick info) - found the following :

 

The proper name Achird was apparently first applied to Eta Cassiopeiae in the Skalnate Pleso Atlas of the Heavens published in 1950, but is not known prior to that.[14] Richard Hinckley Allen gives no historical names for the star in his book Star Names: Their Lore and Meaning.[15] In 2016, the IAU organized a Working Group on Star Names (WGSN)[16] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[17] It approved the name Achird for the component Eta Cassiopeiae A on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[12]

 

My usual conclusion. Too many "proper names" for stars, which adds another layer to getting a useful identification for them - except for the common ones such as Sirius, Rigel, etc. What appears on the atlas or map or software package in front of you is not what anyone else is looking at. Please - provide an easy identifier as well - Eta Cas immediately tells us where to start. Achird (sounding like a sneeze) does not.

 

Otherwise, very nice observing report, Aubrey. Regarding the star colours of STF 16 : Webb gives no colours, but Smyth describes the pair as "A, pale white" and "B...purple". Of course, some of the purple could be from Smyth's achromatic refractor, but with star A not similarly affected, despite being brighter, it does suggest that B is of a different colour, and it is just bright enough to show colour with a 15cm refractor (as Smyth used). Perhaps, Aubrey, you were seeing a real colour 'orange, or red', which Smyth saw as purple because of the chromatic aberration of his refractor, whereas yours, being an apo design, would not be likely to produce that effect, but should be much closer to colours seen with a reflector.

 

I then looked for information via Simbad. No spectral type for B, but the magnitudes in B and V give a B-V colour index of 0.34, which suggests a slightly yellowish colour for a mid-F spectral type. This leaves elements of the puzzle intact. Not solved. Next we need someone with a reflector of good aperture - to get enough light for colour perception - to observe it, perhaps 20cm or, better, somewhat larger.


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#7 c2m2t

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Posted 25 December 2019 - 08:46 PM

Gents!

I believe I have ENG 88 imaged as well ! I will add an image when I return after the in- law...in my case...the outlaw...party.

Cheers, Chris


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#8 flt158

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Posted 26 December 2019 - 08:35 AM

Hello, Fred. 

I am, as ever, so glad to hear from you yet again!

That "sneeze" binary comment on Achird made me chuckle. 

How apt is that!

All your details I did recently read about in an Irish astronomy magazine are totally correct. 

By the way, I do personally reckon that Eta Cassiopeiae is my favourite 4th magnitude double in northern hemisphere skies. 

 

As I said last night, it is vital I recheck the colours of Stf 16 the next clear night I get. 

I cannot understand where I got that mysterious colour for the secondary from. confused1.gif 

And I am very much persuaded that my large apo refractor ought to kill false colours. 

 

Unfortunately my next 4 to 5 nights are very overcast. frown.gif

I am also starving to observe ENG 88. 

Chris's image should be a goodie!!ohmy.png

 

All the best from Aubrey. 



#9 c2m2t

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Posted 28 December 2019 - 12:54 PM

Hi Aubrey!

I was sure that I had imaged ENG 88 on my most recent imaging trip to Arizona...but alas, I was incorrect. The good news is that it is on my hit list for Cassiopeia. From my home observatory, the north sky, for the most part is obstructed but there are small windows of opportunity...I'll keep a watch out for an opportunity. Worse case, it will have to wait till spring when I can setup in other places in the yard...or someone else has beaten me to it! In any case it will get done and I will post or send you a copy.

Cheers, Chris.


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#10 ssmith

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Posted 28 December 2019 - 06:40 PM

Hi Chris -
 
I was looking forward to seeing what you were going to post but since that may take a while I will put up one of my own.  
 
ENG 88 Cass 120mm 11-29-17 crop2 resize.jpg

Edited by ssmith, 29 December 2019 - 09:22 AM.

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#11 c2m2t

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Posted 29 December 2019 - 10:17 AM

Hi Steve!

Thanks for adding your fine image. It will provide some closure at this point!I will add mine later as it becomes available. Have a great New Year.

Cheers, Chris.



#12 John Fitzgerald

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Posted 29 December 2019 - 11:07 AM

The name Achird is shown for Eta Cas in Sky Safari 6.


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#13 fred1871

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Posted 29 December 2019 - 07:21 PM

Makes my point again - it depends on which map system you have whether the name is used.

 

And - having the name appear in a note here on CN - unless you already know the name you have to go hunting the name lists to discover which star is referred to. Otherwise, telepathy is assumed.


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#14 John Fitzgerald

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Posted 29 December 2019 - 08:38 PM

The WGSN (Working Group on Star Names) approved the name Achird for Eta Cas on 5 Sept 2017.  It will likely be used in some forthcoming works.  Personally, I had rather use the greek letter and constellation for a bright star name unless it is a commonly known first magnitude star or a well known one like Polaris or Mizar. 

 

BTW, the latest edition of Stellarium is using Achird for Eta Cas name also.


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#15 flt158

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Posted 04 January 2020 - 04:30 PM

Good evening, all.

 

These were my observations on Friday 3rd January 2020. They are all still in Cassiopeia. No less than 5 doubles, one triple and one sextuplet star system which Ray (The Ardent) informed us all about.

The first 3 systems are very close to Beta Cassiopeiae (Caph). So close, in fact, it is relatively easy to fit all 3 and Caph in the same 2 degrees field of view (fov) at 40X.

 

All my figures are from www.stelledoppie.it

 

1. ARY 7 is an optical double with magnitudes 7.8 and 8.3. Sep = 124.2". PA = 4 degrees. You could drive a bus through the huge gap of course. Easily split at 40X. Both stars are white. ARY stands for Robert Argyle.
.
2. ARY 8 is amazingly a true triple star with magnitudes 8.1, 8.6 and 8.3. Sep's = 39.1" and 104.3. The PA's are 100 and 43 degrees. Very attractively split at 40X. All 3 stars have slightly blue tints.

 

3. ARY 9 is an optical double with magnitudes 7.1 and 8.6. Sep = 138.7". Which is massive, I know. PA = 83 degrees. The colours are far more interesting: blue and yellow.

 

These next 2 doubles are very close to Caph also, and they are both utterly wonderful i.e, good and tight.

 

4. Stf 3057 might not be a true double, but it is good and tight at 112X. The magnitudes are 6.7 and 9.3. Sep = 3.9". PA = 298 degrees. I also used 140X and 167X. Both stars are white

 

5. Stf 3062 is a true binary with magnitudes 6.4 and 7.3. The separation = 1.5". PA = 5 degrees. Both stars are white. I needed 140X to split it. But I have to say I could fit in both doubles at 167X. They are less than 14 arc minutes apart.

 

6. Sigma Cassiopeiae is another stunner. It's possible it may not be a true binary. The magnitudes are 5 and 7.2. Sep = 3.1". PA = 326 degrees. Nicely split at 112X. Both stars are white. It was my 1st time to observe it.

 

7. And so to the sextuplet ENG 88. This is truly a WOW spectacle! Thank you, Ray. I was totally amazed I could see all 6 components at a lowly 40X. But of course I had to push the magnifications up and up. The magnitudes are 7.2, 10.6, 10.8, 9.8, 10.9 and 9. The separations are 170.6", 146.7", 228.9", 167.4" and 281". The PA's are 215, 165, 198, 147 and 197 degrees. The highest power I used was 167X. The brightest star is yellow and its designation is TYC 4008 18. I realise the Trapezium in the Orion's Nebula is very famous. But do consider have a go at ENG 88. I promise you will not be disappointed at whatever power you use! You will find it near Tau Cassiopeiae - just as Ray said. 

 

By the way, my sky conditions became very bad as 10 pm approached. 

Can someone check out the colours of Stf 16?

And I wouldn't mind I was about to re-observe it. 

 

I might have clear skies again on Monday 6th January. 

But weather forecasts often change. 

 

Kind regards, 

 

Aubrey. 


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