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Carbon Star Newbie

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#26 Dave Mitsky

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Posted 13 August 2019 - 05:03 PM

My favorite carbon stars are V Aquilae, S Cephei, DY Crucis, V Hydrae, R Leporis, and T Lyrae.  DY Crucis is the ruddiest star that I've ever seen.

 

Since carbon stars are variable stars, there is more information available in the Observational Astrophysics forum.

 

Additional lists of carbon stars can be found at the following URLs:

 

https://www.skyandte...-red1203201401/

 

https://www.skyandte...g-carbon-stars/

 

http://www.aho.ch/pi.../carbonred1.htm

 

http://www.astrosurf...iar2/carbon.htm

 

http://www.nckas.org/carbonstars/

 

Dave Mitsky



#27 aeromarmot

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Posted 13 August 2019 - 09:44 PM

Many carbon stars are indicated with "( c )" in the Sky &Telescope Pocket Sky Atlas.  Many of us already own that reference.

 

Some carbon stars seem to lose a little of their beauty when trying to shine through the greenish airglow. Airglow contaminates the red and gives the carbon star a brownish tint.  I have noticed that when I'm using a  broadband filter that removes the airglow and that possesses a wide, red passband, the red comes shining through. It becomes much easier to separate carbon stars from the others.

 

I'm not sure why the ultra-red ones like T Lyr and Hinds Crimson seem to be able to burn through the airglow with ease. If you have access to such a filter, give it a try.  There's almost a qualitative difference between carbon stars and normal ones.

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C

So would something like a 23A red filter work?



#28 theApex

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Posted 13 August 2019 - 11:00 PM

So would something like a 23A red filter work?

I'd always been in the impression any one filter color kinda cancels out objects of that same color, therefore decreasing their contrast against the beckground. plus that doesn't apply to point+like sources, such as stars. Or does it?

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Edited by theApex, 13 August 2019 - 11:01 PM.


#29 aeromarmot

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Posted 13 August 2019 - 11:11 PM

I'd always been in the impression any one filter color kinda cancels out objects of that same color, therefore decreasing their contrast against the beckground. plus that doesn't apply to point+like sources, such as stars. Or does it?

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Hmmm.  don't know.  I've only used my filters on planets.  I'll drop a report in a couple of weeks after my next star watch.



#30 Cames

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Posted 14 August 2019 - 07:25 AM

So would something like a 23A red filter work?

I've never tried a straight colored filter.  I think that a straight filter would affect the color of all the stars. I doubt it would work.

 

The broadband filter I used is an 'interference filter'. It allows only certain colors to shine through; but it blocks those in the middle of the visual spectrum where wavelengths of light pollution and air glow tend to aggregate.  Neither have I tried the Neodymium class of filters. It's only the broadband interference filter where I notice the carbon star enhancement.  Broadband filters are expensive and not many people have one.  I just happened to have one so I used it.

 

I happened to notice the effect on carbon stars. I'm by no means an expert. Nor can I comment on astrophysical principles involved. I'm strictly an observational amateur.

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C


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#31 Starman1

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Posted 14 August 2019 - 02:22 PM

Try this:

http://saguaroastro.org/sac-downloads/

Go down the list to the red stars database and click on it to download.

One thing:

Most carbon stars are variable and the ranges also vary, so take the magnitudes with a grain of salt.

Most on-line references do not show an average range, but only list one magnitude, which may have been taken at any point in the range.

that's why you will find many on-line discrepancies for the magnitudes of particular carbon stars.

So read the notes field on each star in the list for more information.


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#32 theApex

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Posted 14 August 2019 - 04:03 PM

Also, as usual, numbers don't reflect reality.

Take what's been said about DY Crucis, for example: in good old Albireo style, the color clash of its scarlet red with Beta Crucis's beautiful whiteish blue makes up for the awe factor - not any number on its own.

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