Table file output

The individual data, reduced as described above, are put into a simple output table file named ``results.tbl''. Its columns give both MJD and heliocentric Julian Date (minus 2400000); the name of the object; the band; and the corresponding standard magnitude. This makes the results of the reductions available for further processing with MIDAS utilities.

For example, although the table entries are written in the same order they are printed in the logfile (star by star, so that the necessary color data are adjacent), they can be rearranged into chronological order, or by passband, with the SORT/TABLE command. Columns can be extracted to a new table, using PROJECT/TABLE. You could interpolate the values of a comparison star to every time in the table by using FIT/TABLE or REGRESS/TABLE, and then use COMPUTE/TABLE to subtract these from the values for a variable star to produce differential photometry.

Additional columns could be transferred from the original data to the new table, using PROJECT/TABLE and JOIN/TABLE or MERGE/TABLE, so that correlations and effects not looked for by the reduction program can be detected. In general, because the PEPSYS package makes heavy use of table files, the user should try to become familiar with the utilities MIDAS provides to deal with them.