概要
Español: Comparación del tamaño y color 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
sunrad=0.3in;
alpharad = 1.227*sunrad;
betarad = 0.865*sunrad;
proximarad = 0.145*sunrad;
gap = 0.8*sunrad;
pair sunpos, alphapos, betapos, proximapos;
sunpos = (0 + gap + sunrad, 1.9*sunrad);
alphapos = sunpos + (sunrad + gap + alpharad, 0);
betapos = alphapos + (alpharad + gap + betarad, 0);
proximapos = betapos + (betarad + gap + proximarad, 0);
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); % Color is fff1ed
label.bot(btex Sun etex, sunpos - (0, sunrad)) withcolor white;
fill fullcircle scaled (2*alpharad)
shifted alphapos
withcolor (1,0.960,0.949);
label.bot(btex $\alpha$ Centauri A etex, alphapos - (0, alpharad))
withcolor white;
fill fullcircle scaled (2*betarad)
shifted betapos
withcolor (1,0.878,0.737); % ffe0bc
label.bot(btex $\alpha$ Centauri B etex, betapos - (0, betarad))
withcolor white;
fill fullcircle scaled (2*proximarad)
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.)
References
- I took the star colors from [1], which indicates they're only approximate. Apparently there are inherent difficulties in representing a star's color on a computer monitor.
- I took the star radii from [2].
derivative works
このファイルの派生的著作物: