\documentclass[svgnames,a4paper]{standalone}
\usepackage[T1]{fontenc}
\usepackage[frenchb]{babel}
\usepackage{bera}
\usepackage{xcolor}
\usepackage{pst-caelum}

\def\toCaelum#1#2{%
  \ftf8{-(#2-90)/20};\ftf8{-(#1+90)}%
}

\def\pGris(#1,#2){\psdots[linecolor=DimGray,dotsize=6pt](\toCaelum{#1}{#2})}


\begin{document}
\begin{pspicture}(-7,-7)(7,7)
% Ciel de Paris le 21 décembre 2021 à 18h21m TU
\psset[caelum]{
  lon=-2.3,lat=48.805,
  year=2020,month=12,day=21,hour=18.35}
\caelum{Sky}
\caelum[linecolor=MidnightBlue!90!LightBlue,linewidth=0.5pt]{Graticule}%
\caelum[linewidth=0.2pt,linecolor=DimGray]{Boundaries}
\caelum[magmax=8,fillcolor=White]{Stars}
% \caelum[linewidth=0.2pt,fillcolor=Goldenrod]{Asterisms}
% \caelum[linecolor=DimGray]{Graduations}
% \caelum[linewidth=0.3pt,linecolor=Yellow]{EGalactic}
\caelum[linewidth=0.3pt,linecolor=Crimson]{Ecliptic}
\psdots[linecolor=Yellow,dotsize=6pt](\Sun)
%\caelum[textcolor=DarkOrange]{Abreviations}
\rput[r](6.5,-5.9){\sf\small\xintTheJD}
\rput[r](6.5,-6.2){\sf\small\xintTheTS}
\rput[r](6.5,-6.5){\sf\small\xintTheDate}
\rput[l](-6.5,-6.5){\small\xintTheLocation}
\end{pspicture}
\end{document}