\begin{table}%t1
%\centering
\par
\caption{\label{tab1}Observational circumstances.}             % title of Table
\begin{tabular}{l c c c c c}        % centered columns (4 columns)
\hline\hline                 % inserts double horizontal lines
Date &   $r$   & $\Delta$ & $\alpha$ & filter & Observatory \\    % table heading
     & (AU)  &   (AU)   &   (deg)  &        &  \\
\hline                        % inserts single horizontal line
31 Mar. 08 & 2.387 & 1.442 & 10.05 & vr & Kharkiv \\
10 Apr. 08 & 2.370 & 1.385 &  5.77 & vr & Kharkiv \\
12 Apr. 08 & 2.368 & 1.378 &  5.03 & VR & Kharkiv \\
17 Apr. 08 & 2.359 & 1.361 &  3.50 & VR & TNG \\
18 Apr. 08 & 2.358 & 1.359 &  3.36 & VR & TNG \\
19 Apr. 08 & 2.356 & 1.357 &  3.29 & VR & TNG \\
20 Apr. 08 & 2.354 & 1.355 &  3.30 & VR & TNG \\
02 May 08 & 2.335 & 1.353 &  7.34 & VR & Kharkiv \\
04 May 08 & 2.331 & 1.356 &  8.27 & BVR & Kharkiv \\
10 May 08 & 2.322 & 1.372 & 11.01 & VR & Kharkiv \\
11 May 08 & 2.320 & 1.375 & 11.46 & VR & Kharkiv \\
31 May 08 & 2.287 & 1.485 & 19.38 & VR & Simeiz \\
02 Jun. 08 & 2.284 & 1.499 & 20.01 & VR & Kharkiv \\
03 Jun. 08 & 2.282 & 1.507 & 20.33 & VR & Kharkiv \\
\hline
\end{tabular}
\end{table}