SCACQ provides an Object Coordinates facility to manage lists of sources and their coordinates. The menu is shown in Figure 4.6.
This utility requires the preparation of a text file with one of the following formats.
In column-specified format the first line of the file specifies the field names and their columns:
#sc:c name 0-15 ra 16-26 dec 28-38 pmr 40-44 pmd 46-50 epoch 52-57 ofr 59-62 ofd 64-67 comment 69-100
(In the file, all the desired entries must be contained on the first line!)
The ``#sc:c'' is required. An entry such as ``name 0-15'' means that the source name will appear in columns 0 to 15. The following lines in the file must all correspond to the format specified by this line, i.e.:
Alpha Lyr 18:35:14.66 +38:44:09.7 171 285 1950.0 58 73 [N]=0.0
In delimiter-specified format the first line specifies the fields and delimiters for the rest of the file. Possible delimiting characters are !#$%&',/[]:; < = > @|{} and TAB (ascii 9).
#sc:d name:ra,dec,epoch,ofr,ofd;comment
In this format the ``#sc:d'' is required, and the following lines must contain the correct sequence of fields and delimiters, but the columns in which they appear are not important:
Alpha Lyr: 18:35:14.66 , 38:44:09.7 , 1950.0, ofr, ofd ; [N]=0.0
The following keywords are available:
name : Object name (required)ra : Right Ascension (required)
dec : Declination (required)
pmr : Proper Motion in right ascension, arcsec per century (optional)
pmd : Proper Motion in declination, arcsec per century (optional)
epoch : The epoch of the coordinates
defaultepoch : The default epoch to use when you don't want to specify the epoch on each line. Eg: defaultepoch 1950 treats all the coordinates as 1950.0. Either epoch or defaultepoch must be present, and the two cannot be combined.
ofr : RA Offset to guide star in arcsec. (East positive)
ofd : Dec Offset to guide star in arcsec. (North positive)
comment : An arbitrary comment string that is displayed but not processed by the program.
After preparing such a file (several examples with lists of calibrator stars and other sources are already present on ezra), click on the Object Coords button to bring up the Telescope Coordinates Entry window. Type a file name (with path unless the file is in the /u/scuser directory) on the Load file line and press Return. The program will process the file and display it in the window. You can sort the file in three ways using the Name, RA, and None (displayed in the same order as in the original text file) buttons. Use the scroll bar to move up or down through the file, or the Find text-mode entry line to have the program search for any desired string in the list. Highlight a desired source by clicking on its line with the left mouse button.
Once a source is selected, its coordinates can be transmitted to the telescope operator by pressing Send Chosen. The source name, coordinates, epoch, and proper motions (if present) will be transmitted through the serial port to the operator's computer terminal. He or she simply has to execute a go command to enter the coordinates.
The ofr and ofd keywords are used to command the offset guider. If MIRELLA is being run in an XTERM and the Guider Offset checkbox in the Object Coordinates menu is set to include, then the offset guider will be moved to the (ofr, ofd) position using the og r command when Send Chosen is pressed. If (ofr, ofd) = (0, 0) no guider command is sent; use these settings when there is no available guide star.