
\documentclass[12pt]{standalone}
\usepackage{pgfplots,pgfplotstable}
\usepgfplotslibrary{statistics, groupplots}
\pgfplotsset{compat=newest}

\begin{document}
\begin{tikzpicture}
	  \pgfplotsset{colormap={stars}{[0.1cm] color(0cm)=(blue); color(1.8cm)=(white); color(2.1cm)=(yellow); color(2.6cm)=(red); color(3cm)=(red!50!black)}}
	  \begin{loglogaxis}[
		  width=\textwidth,
		  height=7.5cm,
		  x dir = reverse,
		  xlabel = Temperature (K),
		  ylabel = Fraction of Sun's Luminosity,
		  ticklabel style={font=\tiny},
		  xtick = {3000, 6000, 10000, 25000},
		  xticklabels = {3000,6000,10000,25000},
		  colormap name= stars,
		]
		\addplot[scatter, scatter src=-x, draw=black, only marks, mark size = 1pt] table[x index=0, y index=1] {./HR_Data.csv};
		\node at (axis cs: 10^4.5,10^-4) {O};
		\node at (axis cs: 10^4.2,10^-4) {B};
		\node at (axis cs: 10^3.95,10^-4) {A};
		\node at (axis cs: 10^3.85,10^-4) {F};
		\node at (axis cs: 10^3.7,10^-4) {G};
		\node at (axis cs: 10^3.6,10^-4) {K};
		\node at (axis cs: 10^3.4,10^-4) {M};
	  \end{loglogaxis}
\end{tikzpicture}


\end{document}
