title: How to format the title in ggplot2
body: <p>I have a data with a name "catch" and the observations are:</p>
  
  <pre><code>x  y
  0.50 3.66
  0.63 3.95
  0.77 5.82
  0.92 7.38
  1.07 8.58
  1.24 9.31
  1.42 9.52
  1.61 9.52
  1.81 9.58
  2.04 9.54
  2.29 9.56
  2.56 9.44
  2.87 9.07
  3.21 8.61
  3.61 7.92
  4.09 7.04
  4.67 5.93
  5.43 4.52
  6.52 2.90
  8.43 0.63
  </code></pre>
  
  <p>I used this code in R:</p>
  
  <pre><code>library(ggplot2)
  ccplot &lt;- ggplot(data = catch, aes(x = x, y = y)) +
            geom_point(shape = 19, colour = "#0072B2")
  
  ccplot &lt;- ccplot + geom_abline(intercept = 14.58, slope = -1.85, col = "#D55E00")
  
  ccplot2 &lt;- ccplot + 
             xlab("time") + 
             ylab(expression(paste("ln[C(L1, L2)]/(", Delta, "t)")))
  
  ccplot2 + ggtitle(expression(paste("Length-Converted Catch Curve\n(for Z=1.85; M(at 23"*degree*"C)=0.69; F=1.16; E=0.63"), hjust = 0))
  </code></pre>
  
  <p>The problem arises when the printed plot have a large (distant) space between the number 23 and the degree symbol.</p>
  
  <p><a href="https://i.stack.imgur.com/JuNvA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JuNvA.png" alt="The plot printed with the above code"></a></p>
  
  <p>How do I format the title so that the space be gone? Or is there any other method to accomplish the proper title in ggplot2?</p>
  
  <p>Thank you in advance.</p>