🚀 go-pugleaf

"Mike Williams" <nospam@econym.demon.co.uk> wrote in message 
news:qCfJvGARqVUDFwDT@econym.demon.co.uk...
| Wasn't it Androcles who wrote:

Yes it was.

| >
| >Assistant Professor "Paul B. Andersen" <paul.b.andersen@hia.no> of :
| >Agder University College (HiA)
| >Serviceboks 422, N-4604 Kristiansand, NORWAY Tel (+47) 38 14 10 00 
Fax
| >(+47) 38 14 10 01
| >has executed the biggest fumble ever seen in the history of
| >sci.physics.relativity
| >in message
| > news:dir555$965$1@dolly.uninett.no...
| >
| >"The spectral class [of stars]  is determined by the relative 
positions
| >and intensities
| > of the absorption lines, and these are unaffected by a Doppler 
shift."
|
| I can't see anything wrong with that.

You can't, huh... not too bright, are you?
http://instruct1.cit.cornell.edu/courses/astro101/java/binary/binary.htm
What would you like, the pretty colours to move instead?


|
| For distant very stars that have spectra strongly affected by red 
shift,
| you can't classify them by how red or blue they are, because the 
colour
| has been shifted by an unknown amount.
|
| What you have to do is look for the patterns formed by the absorption
| lines. The lines may be shifted down the spectrum, but the positions 
of
| the lines relative to each other doesn't change, and allows you to
| recognise the patterns and identify which line is caused by which
| element.
|
| What you could then do is to compare the positions of those lines to a
| reference spectrum, calculate the red shift,

What shift? There isn't any shift according to Andersen (or YOU) since
you find nothing wrong with his statement.


and work out what colour
| the star actually would be if there were no red shift. But that's not
| what they actually do in practice, once they've worked out which line
| corresponds to which element, they compare the relative intensities of
| those lines.
|
| The strongest lines in O type stars correspond to ionized helium. For 
B
| type stars its neutral helium. A type stars have neutral hydrogen as 
the
| strongest line. F: Calcium II in a singly ionized state. G: neutral
| Calcium II and other neutral metals. K: Calcium and Iron and some 
faint
| molecular lines. M: lines corresponding to molecules like Titanium
| Oxide.
|
| -- 
| Mike Williams
| Gentleman of Leisure.
Wrong... IDIOT of Leisure.
Androcles.