Celestia Forums

Hi it's me again

I have been looking around and haven't found a conclusive answer to the question above.
So again, what SpectralTypes does Celestia know and understand if i write them into an stc file?
Is there a guide, documentation for it, that i missed?
Help would really be appriciated. There are good guides for the ssc-files, but one for the stc-files seems to be missing.
Since i am at the moment trying to figure stars, magnitudes, and all that stuff out, i would find something like this very usefull. If there is nothing there yet, i could perhaps be tempted to write one, but only a brain-dead one

But first i need some answers.

Regards,

Guckytos

O,B,A,F,G,K,M,L,T
R,S,N,C,WC,WN
D (for a white dwarf)
Q (for a neutron star)

Grant

Thanks grant!!

You missed one: X (for a black hole)

Unfortunately it doesn't work very well, because Celestia uses the temperature and apparent magnitude to calculate radius, and the temperature of a black hole is defined as zero - thus the black hole has infinte radius.

Grant,
I remember approximately, from my younger time, the mnemonics to memorize the star clessification:
O Be A Fine Girl, Kiss Me Right Now Sweetheart
Is such classification been slightly modified?

MB

chaos syndrome wrote:You missed one: X (for a black hole)

Yeah, I skipped it deliberately, since you although Celestia "knows and understands" that type, it's not exactly supported in any useful way at present, for the reasons you describe.

Grant

MB wrote:O Be A Fine Girl, Kiss Me Right Now Sweetheart
Is such classification been slightly modified?

Yes, new spectral classes have been formally adopted. I seem to remember an astronomy magazine holding a competition for a new mnemonic, but I don't recall seeing the winner.

Grant

Grant, I guess I need to update my teaching presentations on spectral ID of stars. I need to understand what each spectral letter/temperature/color represents. I've been to some sites that do not have all the letters you listed. Is there a definitive website that discusses (and shows examples of) the star associated with each spectral letter?

Frank

fsgregs wrote:Is there a definitive website that discusses (and shows examples of) the star associated with each spectral letter?

I'm not big on web reference, Frank ... sorry. But no doubt someone here has a favourite they'll share.

Grant

Well.... The APOD has a page showing the major categories (OBAFGKM) See http://antwrp.gsfc.nasa.gov/apod/ap010530.html
NOAO has a similar labelled display at http://www.noao.edu/image_gallery/html/im0649.html

My (perhaps mistaken) understanding is that the others (like RNS and the newer white dwarf and carbon star reclassifications for R and N) are much more specialized classifications, intended for stars that don't quite fit into the original MK spectrographic classification scheme.

Spectral class "L" has been proposed for stars cooler than M9.5 V. See http://cdsaas.u-strasbg.fr:2001/ApJ/journal/issues/ApJ/v519n2/39663/39663.html

See http://www.wordiq.com/definition/Spectral_type for what seems to be a reasonable description of all the classes.

Well i found this website which shows information about the spectral classes and especially gives hints on related readings and links

http://www.peripatus.gen.nz/Astronomy/Index.html

Hope it will help you some, Frank.

Oh btw i am writing an STC-guide and all those classification sheme stuff is going to be packed into it. Since i need to understand it anyway i thought why not write a guide
It is still just in the beginning, but when i think it's more or less complete i am going to post it here.