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8th observed carbon star in Cassiopeia

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#1 flt158

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Posted 16 January 2020 - 12:03 PM

On Tuesday night 14th January 2019, I observed a 9th carbon star in Cassiopeia with my William Optics 158 mm F/7 apochromatic refractor. TYC 3651-650-1 is positioned near the optical double star STTA 251. I could not see it at 40X. But I was successful at 112X. It is so faint with a magnitude of 11.4. Its orange hue was evident at 140X, 167X, 225X and 280X. It is my 8th observed carbon star in Cassiopeia. My 79th overall. Can anyone tell me what its spectral class is? I would be delighted to know. Thank you very much. 

There is a red star immediately to its northeast.Guide 9.1's designation is 3UC284-268448. Its magnitude is slightly brighter at 11.1. So all in all,  it is quite a nice optical double less than 1 arc minute apart. 

 

Clear skies from Aubrey. 

 

 



#2 ssmith

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Posted 16 January 2020 - 04:38 PM

Hi Aubrey -

 

Attached is the SIMBAD data for your Carbon star which turns out to be C3205.  There doesn't seem to be any detailed spectra available for this star - it is simply noted as being "Carbon".  There is a faint double star just to the north  as shown in the thumbnail photo.  It is ALD 121.

 

C3205 Cas Simbad.jpg


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#3 ssmith

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Posted 16 January 2020 - 04:45 PM

Here is a wider shot showing C3205 in relation to STTA 251 and ALD 121.

 

STTA 251 Cas Simbad.jpg



#4 flt158

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Posted 16 January 2020 - 05:55 PM

Hi Aubrey -

 

Attached is the SIMBAD data for your Carbon star which turns out to be C3205.  There doesn't seem to be any detailed spectra available for this star - it is simply noted as being "Carbon".  There is a faint double star just to the north  as shown in the thumbnail photo.  It is ALD 121.

 

attachicon.gifC3205 Cas Simbad.jpg

I'm happy with a spectral class of C for C* 3205, Steve. 

I thank you, yet again, for all your hard work in providing this basic date. 

 

Kind regards, 

 

Aubrey. 



#5 flt158

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Posted 16 January 2020 - 06:05 PM

Here is a wider shot showing C3205 in relation to STTA 251 and ALD 121.

 

attachicon.gifSTTA 251 Cas Simbad.jpg

Hi again, Steve. 

Thank you for providing this highly detailed image of STTA 251 and C* 3205. 

As I am positioned in a Bortle 8 or 9 back garden, I cannot be expected to see A and B of ALD 121. 

B is of magnitude 12.4. 

 

I will look into STTA 251 tomorrow Friday. 

 

Kind regards, 

 

Aubrey. 



#6 flt158

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Posted 17 January 2020 - 10:38 AM

Hey, Steve. 

Could that C star of STTA 251 be a variable?

Maybe it was too faint for me to observe. 

After all I was seeing stars which were equally dim elsewhere on the same night.  

 

Thank you. 

 

Aubrey. 



#7 ssmith

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Posted 17 January 2020 - 10:42 PM

Hi Aubrey -

 

The C component is a rather nondescript star with very little data attached to it.

 

WDS lists its V magnitude as 11.7.

 

Simbad has it at 11.8 but with an "E" as the quality factor which is pretty poor.

 

UCAC4 only gives J & K band magnitudes but when these are converted to V band it gives a value 12.1 which is almost a half magnitude fainter than the WDS value.

 

So it may very well be fainter than you were expecting and out-of-range for your equipment.  I doubt it is variable.


Edited by ssmith, 17 January 2020 - 10:44 PM.

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#8 flt158

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Posted 18 January 2020 - 09:07 AM

Thank you very much for that clarification, Steve!

There is a 12.1 magnitude star east north east of the magnitude 9.1 magnitude secondary on Guide 9.1. 

I only saw it as I increased to Level 8 on the DVD. 

 

So I need to revisit STTA 251 again. 

There are also 3 more doubles in the area too. 

Consequently I will be returning to that section of the sky at the next available opportunity. 

 

Clear skies, 

 

Aubrey. 



#9 The Ardent

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Posted 21 January 2020 - 01:51 PM

Sorry this a a little off topic, but last night I was viewing with 21x 82mm binoculars and noticed RW Cephei appeared much brighter and colorful than I remember. Worth checking out since it’s close to Cas. Super orange color saturation.
I also observed WZ Cas , it’s a sin not to when viewing this area.
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#10 flt158

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Posted 21 January 2020 - 04:20 PM

I am new here and I saw the discussion about Carbon Stars.  These are some of my favorite stars to look at.  The Astronomical League has an observing program dedicated solely to Carbon Stars. It contains 100 stars for the Northern Hemisphere and an additional 28 if you are fortunate enough to get to view the Southern Hemisphere.   

 

You can check it out here:    https://www.astrolea...serving-program

Welcome, 8SEuser. 

 

It is somewhat strange to be discussing carbon stars on the Observational Astrophysics forum on Cloudy Nights. 

But rules are rules and I am agreeable to be obedient to such regulations. 

 

Please do send in any reports you have in the future regarding these extraordinary orange - red stars. 

You might include magnitudes, magnifications and colours when you do. 

There will be those who may be encouraged to follow up on your observations. 

 

Since December 2000, I have the privilege to observe 79 carbon stars. 

And I still have at least one more to find Cassiopeia.  

 

Thank you very much. 

 

Kind regards from Aubrey. 



#11 flt158

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Posted 21 January 2020 - 04:47 PM

Sorry this a a little off topic, but last night I was viewing with 21x 82mm binoculars and noticed RW Cephei appeared much brighter and colorful than I remember. Worth checking out since it’s close to Cas. Super orange color saturation.
I also observed WZ Cas , it’s a sin not to when viewing this area.

Hello, Ray. 

 

Thank you for encouraging us to check out RW Cephei. 

I have looked into this hyper giant variable star. 

It is in Cepheus alright - extremely close to the Lacerta border. 

However, could you check if it is an actual carbon star? 

According to www.aavso.org it is varies from G8 to M2 in a period of 346 days. 

By the way, you've got great binoculars there, Ray!

 

And who could resist WZ Cas?

It truly is a wonderful carbon and double star. 

 

Kind regards from Aubrey. 



#12 The Ardent

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Posted 22 January 2020 - 03:09 PM

Aubrey
RW CEP isn’t officially a carbon star. But I think you can make an exception if properly vouched for.
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#13 MikiSJ

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Posted 22 January 2020 - 03:27 PM

Aubrey

 

Please don not take this as criticism, as it is not - but what is your purpose in ferreting out carbon stars? Do you participate in something like aavso.org.

 

I ask this question as I am looking for more of a purpose than shooting pretty images with my new C11/CGX. I am considering possibly some patrol type work. While I think my mount/OTA is up to patrol work I no longer have a quality CCD/Filter capability - shooting with a newly acquired Nikon D5300.


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#14 Rich (RLTYS)

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Posted 22 January 2020 - 04:43 PM

Most observers observe carbon stars for their beautiful red color and some of them are variables.


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#15 flt158

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Posted 22 January 2020 - 07:32 PM

Aubrey

 

Please don not take this as criticism, as it is not - but what is your purpose in ferreting out carbon stars? Do you participate in something like aavso.org.

 

I ask this question as I am looking for more of a purpose than shooting pretty images with my new C11/CGX. I am considering possibly some patrol type work. While I think my mount/OTA is up to patrol work I no longer have a quality CCD/Filter capability - shooting with a newly acquired Nikon D5300.

I just love them!

 

Rich (RLTYS) has given us the correct answer. 

 

Back in April 2019, a guy called Eric (Cildarith) issued a post titled Simbad 2343 Carbon stars brighter than magnitude 13.0

So I have been discovering these amazing stars in various constellations ever since.  First was Andromeda. Now it's Cassiopeia.   

I also seek out star clusters, doubles and triples in the same constellations. 

 

When you do get your imaging equipment, MikiSJ, please share them with us all here on the Observational Astrophysics forum. 

 

I,for one, will be fascinated with your findings. 

 

Kind regards, 

 

Aubrey. 


Edited by flt158, 22 January 2020 - 07:33 PM.


#16 MikiSJ

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Posted 22 January 2020 - 08:21 PM

When you do get your imaging equipment, MikiSJ, please share them with us all here on the Observational Astrophysics forum. 

 

I,for one, will be fascinated with your findings. 

 

Kind regards, 

 

Aubrey. 

I will, and you keep chasing those red thingys.


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#17 flt158

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Posted 23 January 2020 - 10:02 AM

Aubrey
RW CEP isn’t officially a carbon star. But I think you can make an exception if properly vouched for.

Yes! Of course we can, Ray. 

 

Aubrey. 



#18 tchandler

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Posted 04 February 2020 - 10:05 AM

Hey Aubrey

 

I'm curious to learn the names of the other carbon stars you've observed in Cassiopeia. 

Might they be these? (Spectral type from Sky Safari or BCH). Given the depths of some of the minima, glimpsing them is no small feat.

 

Star - Spec- mag. range

 

S Cas - S4 - 7.9-17.3

U Cas - S3.5 - 7.7-16.0

X Cas - S3.5 - 9.2-12.8

ST Cas - C4.4 - 9.0-10.0 

WW Cas - N0 - 9.1-11.7

WY Cas - Sp (or M) - 7.5-16.0

WZ Cas - C9 - 6.3-8.8 (my favourite of the lot - nicely contrasted with nearby STTA 254, spec B2)  

NQ Cas - C4.5 - 10.6-11.5

 

Best wishes,

 

Trevor


Edited by tchandler, 04 February 2020 - 10:07 AM.

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#19 flt158

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Posted 04 February 2020 - 01:06 PM

Hello, my fellow carbon star enthusiast, Trevor. 

 

The 9 carbon stars I have successfully observed in Cassiopeia are the following:

 

1. X Cas. 

2. ST Cas. 

3. V623 Cas. 

4. W Cas. 

5. WZ Cas. 

6. NQ Cas which is my current favourite because of its gorgeous hue. 

It's breathtakingly beautiful!

7. WW Cas. 

8. TYC 3651-650-1. 

9. IRAS 01184+5121. Which is also called 3UC284-022963. 

 

I have not observed S Cas, U Cas or WY Cas at all. 

 

But maybe I will observe them some time. 

Erich (Cildarith) gave me a list of 2343 carbon stars 1 year ago. 

And I am slowly wading my way through his link. 

 

I have my scope in my back garden for the last time until August 2020 to find one more carbon star in this glorious constellation tonight. 

You see Cassiopeia is getting impossible to view. It's going behind a very tall tree. 

 

How many carbon stars have you observed in the big "W", Trevor?

 

I'm just wondering. 

 

Clear skies to you, Trevor and everyone. 

 

Aubrey. 


Edited by flt158, 04 February 2020 - 01:09 PM.


#20 tchandler

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Posted 06 February 2020 - 10:50 PM

Hey,

 

Well - WZ is my first and only Cassiopeia carbon star, first observed last summer at a star party. 

Tonight, Cassiopeia has gone behind a nimbostratus cloud that's dropping lots of snow.

 

Thanks for recapping the Cassiopeia nine. I'm curious to go after NQ after reading your description. 

 

Trevor


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#21 ssmith

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Posted 09 February 2020 - 05:56 PM

Hey Aubrey -

 

I finally made my way to C3205.  I cant seem to get any consistent photometry of the stars in this area but C3205 seems equal to or brighter than ALD121-A.

 

Heres a photo:

 

ALD121 & C3205 Cass C9 2-8-20 10fr.jpg

 

 


Edited by ssmith, 09 February 2020 - 09:26 PM.

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#22 flt158

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Posted 09 February 2020 - 06:52 PM

What a lovely image, Steve, you are giving us all here!

C* 3205 is truly a very fine carbon star.

 

Cassiopeia must be still in a most favourable position for you. 

I'm thinking of having a break from Cas until August when I will have a very good view of it again. 

And I do have at least 2 more carbon stars to hunt down.  

 

Oh -I have one question for you, Steve. 

How do you discover the distances of these carbon stars?

I would be most interested in that. 

 

Thank you very much, Steve. 

 

Aubrey. 



#23 ssmith

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Posted 09 February 2020 - 09:21 PM

Hi Aubrey -

 

Determining the distances is really very easy if the distance isn’t given in one of the astronomy apps or in Wikipedia.  Right now the best source for parallax values is GAIA Dr2.

 

Parallax values are usually published in the units of mili-arc-sec per year.  Use the following formula to find the distance in light years:

 

LY =  [1/ (parallax / 1000) ] x 3.26 

 

Rule of Thumb:  The smaller the parallax value the greater the distance

 

For C3205:  Parallax = 0.2737 mas from post #2 above  = 0.2737/1000 = 0.0002737 arc-sec/yr

 

Dist = (1/ 0.0002737 ) x 3.26 = 11,900 ly 

 

There are other methods to determine stellar distances and not all methods are in total agreement with one another. This is the most accessible method for the amateur.  It is most accurate for close stars which have large parallax values which are easy to measure and less accurate as the parallax values get smaller (distances get larger) but it will get you in the stellar ballpark so to speak.


Edited by ssmith, 09 February 2020 - 09:40 PM.

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#24 flt158

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Posted 10 February 2020 - 01:16 PM

Hi again, Steve.

 

You quote: "Right now the best source for parallax values is GAIA Dr2."

Does that link me up with a website?

I googled GAIA Dr2 and I came up with this website:

www.cosmos.eta.int/web/gaia/dr2 

 

Kind regards from Aubrey. 



#25 ssmith

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Posted 10 February 2020 - 02:54 PM

Aubrey -

 

the GAIA data has been incorporated into most of the astronomy databases.  As shown in the screen-shot I posted in this thread the SIMBAD database has this info and this would be the easiest way to access this data.


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