\begin{table}%t1
\caption{\label{tab:log} Log of the Cygnus~X-1 observations analyzed in this
paper.}
%\centerline
{\begin{tabular}[h]{lllll}
\hline\hline
Epoch &~~~Instrument & Observation Period &~Exposure & Observation\\
&&(date yy/mm/dd)&~~~~(ks) &~~~~Type \\
\hline
~~~~~ &~~~~~~~IBIS & 02/11/25--02/12/15 &~~~~~810 &staring, 5$~\times~$5$^a$, hex$^b$\\
~~~~1 & IBIS/SPI/JEM-X & 02/12/09--02/12/11 & 365/365/31 &~~~~5$~\times~$5 \\
~~~~2 & IBIS/SPI/JEM-X & 03/06/07--03/06/11 & 292/296/275 &~~~~5$~\times~$5\\
~~~~3 &~~IBIS/JEM-X & 03/03/24--04/09/10 &~~269/35 &~~~~GPS$^c$ \\
~~~~4 & IBIS/SPI/JEM-X &~~~~~~04/11/22 &~~~8/8/6 & calibration  \\
\hline
\end{tabular}}
Notes:\\
$^a$ 5$\times$5 dither pattern around the nominal target location.\\
 $^b$ Hexagonal pattern around the nominal target location.\\
 $^c$ Individual exposures separated by 6° along the scan path, shifted by 27.5°
in galactic longitude.\\
(Observations indicated on the first line also used, together with epochs 
1--4, for Figs.~\ref{HR1} and~\ref{HR}.)
\end{table}