Sky Charts 

User Guide

Catalog selection

This panel allows you to select the catalogs you want to use and set 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 on.

Stars :


Checkbox : Select or deselect a catalog.
- Catalogs available to generate charts.
- Enter smallest chart width required for the catalog.
- Enter largest chart width required for the catalog.
- Path to the catalog files.
Proper motion : Only the catalogs marked with "pm" have this information. If the checkbox is marked, the program utilizes 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 :
Restrict the star visibility to a certain magnitude according to the chart width.
- Field width range of the chart.
- Magnitude limit.

Nebulae :


Checkbox : Select or deselect the catalog.
- Catalogs available to generate the charts.
- Smallest field width of chart of the catalog.
- Largest field width of chart of the catalog.
- Path to the catalog files.
Nebulae size limits:
Restrict the nebulae visibility to a certain magnitude according to the chart width.
- Field width range of the chart.
- Magnitude limit 
- Dimension limit in minutes.

Planets :


Checkbox : Show or hide the planets.
Path to the files of the planets, comets and asteroids.
Select between geocentric or topocentric position.
Select the drawing type.
See the stars through the planets: this is useful to determine the end of an occultation.

Comets :


Select one or more comets from the list.
The appearance can be a symbol or a drawing representing the total magnitude and 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 however get this information directly from the Internet with the option Online resources.

Asteroids :


Select one or more asteroids from the list.
The appearance can be a symbol or a drawing representing the total magnitude.
The list can be obtained from two sources :

  • Asteroids : This list can be updated annually from the Internet with the option 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 in DOS format (cr+lf for EOL). You can also directelly load this file from the Internet with the option Online resources.
If you want to avoid out-of-memory problems you can limit the size of the list. You can reduce the number of entries to between 5000 and 20000 by only keeping the interesting asteroids. If you want to see all of the 50000 asteroids in the catalog Astorb you should use the option Bulk calculation of asteroids. The result of this operation can be used as an external catalog (already defined in default.opt).

External catalog according to the magnitude :


This is the description of the format of a formatted text file subdivided in columns which is added to the charts if the first column of each entry is not blank. You can specify the largest magnitude which can be used to draw the stars.
The general format of the columns is: position.length.
1- This catalogue 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- Identification name of the object.
7- Right Ascension, hours or decimal Right Ascension.
8- Right Ascension, minutes.
9- Right Ascension, seconds.
10- Sign of the Declination (mandatory if DD MM SS)
11- Declination, degrees or decimal Declination.
12- Declination, minutes.
13- Declination, seconds.
14- Magnitude.
15- Color index B-V.
16,17,18- Description or supplementary information.

Several examples can be found in default.opt.

External catalog according to the size :


This is the description of the format of a formatted text file subdivided in columns which is added to the charts if the first column of each entry is not blank.
The general format of the columns is: position.length.
1- This catalogue 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- Identification name of the object.
7- Right Ascension, hours or decimal Right Ascension.
8- Right Ascension, minutes.
9- Right Ascension, seconds.
10- Sign of the Declination (mandatory if DD MM SS)
11- Declination, degrees or decimal Declination.
12- Declination, minutes.
13- Declination, seconds.
14- Magnitude.
15- Color index B-V
16,17,18- Description or supplementary information.
19- Color, a constant value which corresponds to the colour defined 
    for the stars.
20- Symbol shape, constant value.
    1 : circle.
    2 : square.
    3 : diamond.
21- 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 (thus end of line = LF). It is important to convert them to DOS format (thus 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.

Images 


Images loading options.

Realsky options:
- Select available CD's (North, South, 102 CD).
- Select plate form a list of available plates or automaticaly select the best centered plate.
- Path where you install the support files.
- CD drive path or path where you copy the RealSky files.
- File name for the temporary FITS file used for extraction.
- Using subsampling to automaticaly 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 reduce the file size by a factor two or three .

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