Sky Charts 

This panel allows you to select the catalogs you want to use and set to up their properties. 
Take a look at the catalog presentation for more information on the usage of the catalogs
and their content.

Load and Save buttons:
These two buttons allow you to save a particular configuration to a file and to retrieve it later.

To save the full program parameters use the OK button and then the main menu Preference - Save options.

Use memory cache:
When the box is checked the data for the different catalogs are kept in memory to speed up the display. To limit memory usage the cache is optimized to keep only the last area used. Deactivate this option only if you use a low memory machine (16MB), or if you want to use a catalog for a field of view greater than the authorized maximum, but beware that performance may suffer.

Stars:

Use the first checkbox to select or de-select a catalog.
Enter the smallest chart field of view this catalog is used for. (Field Min)
Enter the largest chart field of view this catalog is used for. (Field Max)
For better performance avoid overlapping multiple catalogs for the same field of view.
If you don't install the catalog in the standard folder, the File Path field is colored red. Use the small directory button on the right to search for the catalog location.

Proper motion box:
Only the catalogs marked with "pm" have this information. If "Use proper motion" is checked, the program uses the proper motion when it calculates the position of the object for the current date.
It is possible to display the proper motion by showing the displacement for a period of 1-9999 years in the form of a line.

Star magnitude limits box:
Restrict the star visibility to a certain magnitude according to the chart width.
Check "Limit" to activate the magnitude limitation to avoid overcrowding the chart.
The table on the right indicates the magnitude limit for each field of view range.

If you check "Continuous" the magnitude limit is calculated to always show the same number of stars for each field of view. In this case only the 35°-90° box is active to set the reference magnitude at 90°.

A second page is used for additional star catalogs. Use it in the same way.

Nebulae:

Use the first checkbox to select or de-select a catalog.
Enter the smallest chart field of view this catalog is used for. (Field Min)
Enter the largest chart field of view this catalog is used for. (Field Max)
If you don't install the catalog in the standard folder, the File Path field is colored red. Use the small Directory button on the right to search for the catalog location.
For better performance and to avoid objects overlapping do not use multiple catalogs for the same type of object and the same field of view. Specifically if you use either the NGC or the SAC, do not use any other for the same chart.

Nebulae limits box:
Restrict the nebulae visibility to a certain size and magnitude according to the chart width.
Check "Limit" to activate the limitation in order to avoid overcrowding chart.
The table on the right indicates the magnitude and size limit for each field of view range.The size unit is arc minute.

Select ">200'" to show the very extended objects, such as Ursa Major cluster, that are not plotted by default to clean up the chart.

Use the New button to add a line for a new catalog and the Delete button to remove the line selected with the cursor.
Click the button at the right to select a new catalog. Select the .hdr file that contains the description for the catalog. In the case of an error the cell is boxed in red.
Then modify the Min and Max field according to the same rules as described for the stars and the nebulae catalogs. The display limitations indicated in the previous pages also apply to these catalogs.
Click the first column to set it to green to activate the catalog.

Images 

Images loading options.

Realsky options:
- Select the available CD's (North, South, 102 CD).
- Select plate from a list of available plates or automatically select the best centered plate.
- Path where the support files are installed.
- CD drive path or path which contains copies of RealSky files.
- File name for the temporary FITS file used for extraction.
- Use sub sampling to automatically limit the temporary file size to a reasonable value.
- Automaticaly apply a low pass filter to limit the compression effect to the sky background.

Remote DSS options:
- Use Gzip compression to download the image file. This reduces the file size by a factor of two or three .

Open Image options:
- To the image editor to modify some parameters or directly to the chart.
- Select default intensity range values used to display the image.

Planets:

Click "Show the planets" to show or hide the planets.
The File Path indicated is where the files of the planets, comets and asteroids are located.
The following options are available:

• Select between geocentric or topocentric position.
• Select the drawing type.
• Show a realistic image of the planet when drawing according to the size and/or magnitude.
• Reference longitude of Jupiter Great Red Spot.
• Show the stars through the planets. This is useful to determine the end of an occultation.
• Show the Earth umbra at the distance of the Moon to visualize a Lunar eclipse.

The button provides direct access to the JUPOS web page to obtain the most recent measurement of Jupiter's GRS longitude.

You may replace the planet's texture file with your own. The files are located in the folder cat\planet.
It is very important to respect the orientation; place the North at top, -180 longitude at left and +180 longitude at right, the meridian 0 must be at the image center. The exception is Jupiter, in which case you must put the GRS at the image center.

Select one or more comets from the list using the mouse and the standard Ctrl or Shift key.
The appearance can be a symbol or a drawing representing the total magnitude, the size of the coma and the length and direction of the tail.
You can enter data for a new comet at the bottom of the screen and save this information in a file by pressing the "save" button.
You can obtain this information directly from the Internet by using the button "Comet elements" or the menu Online resources.

Asteroids:

Select one or more asteroids from the list using the mouse and the standard Ctrl or Shift key.
The appearance can be a symbol or a drawing representing the magnitude.
The list can be obtained from two sources:

• Asteroids CBAT: This list of bright asteroid at the opposition during the current year can be updated annually from the Internet by using the button "Asteroid elements" or the menu Online resources.
   
• Astorb: Edward Bowell, Lowell Observatory The file must be placed in the directory "cat\planet" and it has to be called ASTORB.DAT. Please convert this file to DOS format (cr+lf for EOL). You can also directly load this file from the Internet with the option Online resources.
  Be aware that the size of this file has become very large in the past few year as the number of known asteroids increases rapidly.

The maximum number which can be shown at one time is 30,000. You can change the number of entries by setting "Max.Nb" between 5,000 and 20,000. Enter the number of the first asteroid to be displayed in the "1=>" field.

If you want to see all of the 150,000 asteroids in the Astorb catalog you should use the option Bulk calculation of asteroids. 

This is the description of the format of a star catalog using a formatted text file subdivided in columns or separated by a separator character which is added to the charts if the first column of each entry is not blank.  There are many sample catalogs available to download which can help you learn how this works.

Reserve this option for a small data set or to quickly add a newly discovered nova. For larger catalogs the preferred way is to build a binary formatted catalog using the Catgen tool which is much more efficient.

A right mouse click to a line displays a menu:

• Open a file containing the catalog definition .cdm
• Save the current line to a file .cdm
• Delete the current line

Here is the detailed format for each column:
1- This catalog is active "1" or inactive " ".
2- Catalog name which will be used in the identification 
   of the object.
3- Complete file path.
4- Epoch of the coordinates.
5- Coordinate type, first character = RA type,
   second character = DEC type.
   RA type:
   0 or blank = Right Ascension in hours.
   1 = Right Ascension in degrees.
   2 = Right Ascension in radians.
   DEC type:
   0 or blank = Declination in degrees.
   1 = distance from the South pole (SPD) in degrees.
   2 = Declination in radians.
6- File format:
   F or blank = Fixed format. The field definition indicate the starting position and the length of each element.
   TAB = Variable format. The field separator is a tabulation character. The field definition indicate the field number.
   SPACE = Variable format. The field separator is a blank space character. The field definition indicate the field number.
   any other character = Variable format. The field separator is the specified character. The field definition indicate the field number.
7- Identification name of the object.
8- Right Ascension, hours or decimal Right Ascension.
9- Right Ascension, minutes.
10- Right Ascension, seconds.
11- Sign of the Declination (mandatory if DD MM SS)
12- Declination, degrees or decimal Declination.
13- Declination, minutes.
14- Declination, seconds.
15- Magnitude.
16- Color index B-V.
17,18,19- Description or supplementary information.
20- Highest magnitude in this catalog 

External catalog according to the size:

This is the description of the format of a nebulae (or other object) catalog using a formatted text file subdivided in columns or separated by a separator character which is added to the charts if the first column of each entry is not blank. There are many sample catalogs available to download which can help you learn how this works.

Reserve this option for a small data set or to quickly add a specific object. For larger catalogs the preferred way is to build a binary formatted catalog using the Catgen tool which is much more efficient.

A right mouse click to a line displays a menu:

• Open a file containing the catalog definition .cds
• Save the current line to a file .cds
• Delete the current line

Here is the detailed format for each column:
1- This catalog is active "1" or inactive " ".
2- Catalog name which will be used in the identification 
   of the object.
3- Complete file path.
4- Epoch of the coordinates.
5- Coordinate type, first character = RA type, 
   second character = DEC type.
   RA type:
   0 or blank = Right Ascension in hours.
   1 = Right Ascension in degrees.
   2 = Right Ascension in radians.
   DEC type:
   0 or blank = Declination in degrees.
   1 = distance from the South pole (SPD) in degrees.
   2 = Declination in radians.
6- File format:
   F or blank = Fixed format. The field definition indicate the starting position and the length of each element.
   TAB = Variable format. The field separator is a tabulation character. The field definition indicate the field number.
   SPACE = Variable format. The field separator is a blank space character. The field definition indicate the field number.
   any other character = Variable format. The field separator is the specified character. The field definition indicate the field number.
7- Identification name of the object.
8- Right Ascension, hours or decimal Right Ascension.
9- Right Ascension, minutes.
10- Right Ascension, seconds.
11- Sign of the Declination (mandatory if DD MM SS)
12- Declination, degrees or decimal Declination.
13- Declination, minutes.
14- Declination, seconds.
15- Size.
16- Unit for the size:
    1  : degree
    60 : minutes
    3600: seconds
17,18,19- Description or supplementary information.
20- Color, a constant value which corresponds to the colour defined 
    for the stars.
21- Symbol shape, constant value.
    1: circle.
    2: square.
    3: diamond.
22- Blank=linear scale, 1=logarithmic scale.
(useful if the size has to represent the intensity, i.e. in the 
case of radio sources).

Warning!
Most of the catalogs available on CD-ROM or from the Internet, as well as Astorb.dat, are in UNIX format (end of line = LF). It is important to convert them to DOS format (end of line = CR+LF) before you use them with "Sky Charts" as external catalogs. There are several programs and utilities to accomplish this task. Amongst them the editor PFE or the TLF utility.