# File:Alpha Centauri relative sizes.png

## Summary

Español: Comparación del tamaño y colour de las tres estrellas de Alfa Centauri con nuestro sol.

A comparison of the sizes and colors of the stars in the Alpha Centauri system with the Sun.

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David Benbennick made this image on January 29, 2005 with the following Metapost program as stars.mp:

verbatimtex
\font\foo=cmss9 at 10pt
\foo
etex

pair sunpos, alphapos, betapos, proximapos;

beginfig(1);

fill unitsquare xscaled ((xpart proximapos) + proximarad + gap)
yscaled (2 * (ypart sunpos));

fill fullcircle scaled (2*sunrad) shifted sunpos
withcolor (1,0.960,0.949);   % Colour is fff1ed
label.bot(btex Sun etex, sunpos - (0, sunrad)) withcolor white;

shifted alphapos
withcolor (1,0.960,0.949);
label.bot(btex $\alpha$ Centauri A etex, alphapos - (0, alpharad))
withcolor white;

shifted betapos
withcolor (1,0.878,0.737);  % ffe0bc
label.bot(btex $\alpha$ Centauri B etex, betapos - (0, betarad))
withcolor white;

shifted proximapos
withcolor (1,0.752,0.411);  % ffcc6f
label.bot(btex Proxima etex, proximapos - (0, proximarad))
withcolor white;

endfig;
end;


And I had the following TeX file as stars.tex:

%&latex
\documentclass[10pt]{article}
\usepackage{graphicx}
\pagestyle{empty}
\begin{document}
\includegraphics{stars.1}
\end{document}


Then I ran

mpost stars
tex stars
dvips -mode ljfzzz -D 1200 stars -o
convert -density 1200 -chop 99999x99999+6249+3463 -chop 2479x2095 stars.ps stars.png
pngcrush -reduce -brute -l 9 stars.png stars.crush.png


stars.crush.png was the final output file.

(Apparently it's non-trivial to get dvips to use a given resolution. I would have preferred to use 1600 dpi, but dvips didn't already have a "printer" at that resolution. ljfzzz, at 1200, was the best I could find.)

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 This file is licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license. You are free: to share – to copy, distribute and transmit the work to remix – to adapt the work Under the following conditions: attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). share alike – If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.

## References

• I took the star colors from , which indicates they're only approximate. Apparently there are inherent difficulties in representing a star's colour on a computer monitor.
• I took the star radii from .

## derivative works

Derivative works of this file:

The following pages on Schools Wikipedia link to this image (list may be incomplete):