\begin{table}%t1
     %\begin{minipage}[t]{\columnwidth}			
     \caption{\label{LPComets}Summary of analysis of the distant environment of Long Period Comets.}
     %\renewcommand{\footnoterule}{}			
     %\centerline
{\begin{tabular}{c c c c}
     \hline\hline
      Comet  &$r_{\rm h}^a$& Type of analysis & Reference \\
     \hline
     C/1980 E1 (Bowell) & 13.6 & Broadband CCD photomety & Meech (\cite{Meech88}) \\
     C/1983 O1 (Cernis) & 13.2 & Broadband CCD photomety & Meech (\cite{Meech88}) \\
     & 17.4 & Broadband CCD photomety & Meech (\cite{Meech90}) \\
     & 19.4 & Broadband CCD photomety & Meech (\cite{Meech92}) \\
     C/1984 K1 (Shoemaker) & 8.6 & Broadband CCD photomety & Meech (\cite{Meech88}) \\     
     C/1983 W2 (Hartley) & 8.5 & Broadband CCD photomety & Meech (\cite{Meech88}) \\
     C/1986 P1 (Wilson) & 5.0 & Broadband CCD photomety & Meech (\cite{Meech88}) \\     
     C/1995 O1 (Hale-Bopp) & 13--4 Pre & Analysis of the dust tail by means of & Fulle et~al. (\cite{Fulle98}) \\
      & & the inverse dust tail model &  \\
      & 4.6--2.9 Pre; & Optical (longslit spectra and images) & Weiler et~al. (\cite{Weiler03}); \\
      & 2.8--12.8 Post & long-term monitoring & Rauer et~al. (\cite{Rauer03}) \\
      & 25.8 Post & $VR_{\rm c}$ photometry & Szab\'o et~al. (\cite{Szabo08}) \\
     C/1999 F2 (Dalcanton) & 5.51 & $V$ and $R$ photometric analysis & Szab\'o et~al.
     (\cite{Szabo01}) \\
     C/1999 J2 (Skiff) & 7.14 & $VR$ photometric analysis & Szab\'o et~al. (\cite{Szabo01}) \\
     & 7.24 & IF390 and RX filters photometric analysis; & Korsun \& Chorny (\cite{Korsun03}) \\
     & & modelling of the dust tail & \\
     & 7.11 Pre--10.1 Post & $VRI$ photometry & Meech et~al. (\cite{Meech09}) \\
     C/1999 N4 (LINEAR) & 5.51 & $VR$ photometric analysis & Szab\'o et~al. (\cite{Szabo01}) \\
     C/1999 T2 (LINEAR) & 3.35 & $VR$ photometric analysis & Szab\'o et~al. (\cite{Szabo01}) \\     
     C/2000 H1 (LINEAR) & 3.89 & $VR$ photometric analysis & Szab\'o et~al. (\cite{Szabo01}) \\
     C/2000 K1 (LINEAR) & 6.43 & $VR$ photometric analysis & Szab\'o et~al. (\cite{Szabo01}) \\
     C/2000 SV74 (LINEAR) & 4.24 & vgrz (Gunn) photometric analysis; & Szab\'o et~al.
     (\cite{Szabo02}) \\
     & & CN, CO+ and C$_2$ spectrophotometry & \\
     C/2001 G1 (LONEOS) & 8.32 Pre - 11.22 Post & $BVRI$ photometry & Meech et~al. (\cite{Meech09}) \\
     C/2001 HT50 (LINEAR-NEAT) & 4.60 & SPITZER IR images and spectra & Kelley et~al.
     (\cite{Kelley06}) \\
     C/2001 Q4 (NEAT) & 5.84 & $VRI$ photometry & Meech et~al. (\cite{Meech09}) \\
     & 8.60 & Vis imaging and spectroscopy & Tozzi et~al. (\cite{Tozzi03}) \\
     C/2002 T7 (LINEAR) & 3.52 & NIR spectroscopy & Kawakita et~al. (\cite{Kawakita04}) \\ 
     C/2002 VQ94 (LINEAR) & 6.80 & Vis photometry and long-slit spectroscopy & Korsun et~al.
     (\cite{Korsun06}) \\
     C/2003 A2 (Gleason) & 11.49 Pre--13.97 Post & $VRI$ photometry & Meech et~al. (\cite{Meech09})\\
     C/2003 O1 (LINEAR) & 7.02 Pre--8.18 Post & $VRI$ photometry & Meech et~al. (\cite{Meech09})\\   \hline
\end{tabular}}
\medskip     
\par
$^a$ Heliocentric distance (AU) of observation. Pre: pre-perihelion. Post:
      post-perihelion.
     %\end{minipage}
     					\end{table}