Label several equations with symbols without leaving a blank space

Question

So I am labeling three equations with symbols, each one in a different line. The problem is that when I do this, a huge amont of blank space is left between equations, and I don't like it. Can someone help me fix this? I am open to different ideas like sticking the equations in an array or something like that, but it is important that each one has its own label.

Here is my code:

\[c_1a_1=r_{12}a_2+r_{13}a_3 \label{eq:star1}\tag{$\star$}\] 
\[c_2a_2=r_{21}a_1+r_{23}a_3 \label{eq:star2}\tag{$\star\star$}\]
\[c_3a_3=r_{31}a_1+r_{32}a_2 \label{eq:star2}\tag{$\star\star\star$}\]

This is how it looks: Also, the stars in the second equation are very close and in the third one they are rather separated. How can I fix this?

Answer 1

You first of all should not have consecutive \[...\]. Since tags are in text mode, use text.

Unfortunately, \textstar is currently not defined, but if it ever will be, the definition with \providecommand will be ignored and result in the same output.

(Note: twocolumn is used just to make a smaller picture.)

\documentclass[leqno,twocolumn]{article}
\usepackage{amsmath}
\providecommand{\textstar}{\ensuremath{\star}}
\begin{document}
\begin{align}
c_1a_1 &= r_{12}a_2+r_{13}a_3 \label{eq:star1} \tag{\textstar} \
c_2a_2 &= r_{21}a_1+r_{23}a_3 \label{eq:star2} \tag{\textstar\textstar} \
c_3a_3 &= r_{31}a_1+r_{32}a_2 \label{eq:star3} \tag{\textstar\textstar\textstar}
\end{align}
\end{document}

What's the problem with $\star\star\star$? \star is an operation symbol, but if it's used “out of context” it will behave as an ordinary symbol. So, the first \star is ordinary, the last one is ordinary, but the middle one retains its operation symbol nature, so TeX adds spaces.