User-Defined Data dialog box (Data | User-Defined Data)

Use the options in this dialog box to add or remove celestial objects or other user-defined points to the Virtual Sky.

There are two methods for adding user-defined data.

Press CONTROL+CLICK on the Virtual Sky. By default, a Reference Point will be added at the current coordinates. Click Data | User-Defined Data to edit the properties of the user-defined data.
Click Data | User-Defined Data and then click Add Entry. Edit the properties of this entry, to define its Data Class, Object Type, Label (for an object with its Data Class defined as type Label), Command (when applicable), Magnitude (when applicable), and Epoch 2000.0 Coordinates.

Visible

Mark this option to show the user-defined data on the Virtual Sky.

Snap To

When data points are added by CONTROL+clicking on the Virtual Sky, they can add at any location on the display. If you wish to add a point that has the exact same coordinates as an object on screen, select the Snap To option for the type of object you want to use as a source of coordinates. For example, to draw a constellation line between two stars, select the Snap To Star option.

Snap To Option	Description
Cursor Position	Point will be logged at the cursor position and will not snap to any object.
Nearest Star	Cursor will jump to the nearest star. If no star is near the cursor, no point will be added.
Nearest Non-stellar	Cursor will jump to the nearest non-stellar object. If no object is near the cursor, no point will be added.

Add Entry

Click this button to add a new entry to the Number Entry list using the current Entry Properties settings. The contents of the new entry can then be edited as necessary.

Delete Entry

Click this button to remove the currently selected entry.

Center

Click this button center the selected User-Defined Data entry on the Virtual Sky.

Remove All

Click this button to remove all entries from the Entry Number list.

Entry Properties Group

The Entry Properties group contains options that define the coordinates and data class, and object type of user-defined object.

Data Class

The Data Class determines how the object will be plotted on the Virtual Sky. The table below lists the different classes of data.

Data Class	Description
Objects/Points	Select this type to add objects such as stars, galaxies, nebula, etc.
Labels	Select this type if you wish to add labels to existing objects.
Lines/Polygons	Select this type to add connecting lines. The line drawn is dependent on setting of the line drawing Command option.

Object Type

Like all objects on the Virtual Sky, each user-defined entry has a Celestial Object type with properties that can be changed on the Display Properties dialog box.

Label

Any text entered in this text box will be displayed on screen at the coordinates of the User-Defined Data entry. Typically, this field is only used when the Data Class is set to Labels, but the other two data classes (Points/Objects and Lines/Polygons) can also have text labels associated with them.

Command

The options in this list box apply only to User-Defined Data that has the Data Class of Lines/Polygons. Each option is described below.

Command	Results	Entering from the Virtual Sky
Move To	Positions the drawing "pen" at the coordinates of the current entry.	Hold down the CONTROL key while clicking at the desired point on the Virtual Sky.
Line To	Draws a line from the previous position (whether from a Move To or a Line To command) to the current position.	Hold down CONTROL+SHIFT while clicking on the desired point on Virtual Sky.

Magnitude

The magnitude entry applies only to User-Defined Data using the Stars object type. All other object types are displayed using the symbol of the corresponding type. The magnitudes entered here for a User-Defined Data entry are also saved to exported text files.

Hrs, Mins, Secs and Degs, Mins, Secs

When an entry is added from the Virtual Sky using CONTROL+Click, the coordinates of the entry are automatically set and can be examined using this dialog box. If you wish to manually enter or edit coordinates, use these text boxes.

If you wish to enter the coordinates in decimal form rather than in hours/degrees, minutes and seconds enter the value in the Hours/Degrees text box. For example, 12.51 hours is automatically converted to 12 hours 30 minutes 36 seconds.

Similarly, if you enter a negative value for the declination, the entire value will be assumed to be negative and the object will appear on the Southern half of the celestial sphere.

Precess

The Precess dialog box allows precessing coordinates from one epoch to another and is accessed by clicking the Precess button. Once the two epochs have been entered (From and To), click OK to precess the coordinates of the current entry to the new epoch.

North/South

Specify the hemisphere for the user-defined data entry.

Exporting User-Defined Data to a Text File

Once data has been added to the Sky Document and the document is saved, it can be exported to an ASCII text file for use as source of data for a permanent Sky Database. Data contained within a Sky Document is available only when that document is loaded, whereas SDBs are available to all documents. Sky Documents contain data that is specific to the document; SDBs contain data that is not document specific.

The two methods for adding data to Sky Documents, manual entry or cursor entry, provide an easy yet powerful means of entering coordinate data. Using the Export button on the User-Defined Data dialog box, these data can be saved to an ASCII text file and be used to create an SDB that is available to all Sky Documents.

To Export User-Defined Data to a Text File:

Click Browse to select the name of the text file. The default text file name is "Untitled.txt" and will be created automatically if it does not already exist. TheSky will overwrite existing text files, so make sure that you always backup your data.
Add comments you wish to appear in the text file preceding the data. A semi-colon precedes a comment (;), so this line is ignored if a Sky Database is compiled from this text file.
Mark the As Polygons option to export the User-Defined Data as polygons, rather than individual objects.
Click Export .

If the specified text file already exists, the local user data is appended to the end of the file. After the User Data has been saved, you will be given a choice of whether to remove all User Data or to retain it. Removing existing data is recommended.

For example, if you were adding areas of nebulosity by defining regions using the cursor, you would typically add the points for one nebula, then export them to the text file. Once exported, the User Data should be cleared so that subsequent data exports do not contain data for the previous region.

Note that SDBs usually contain only a single type of celestial object. When exported, the header in the text file specifies the object type.

Browse

Click this button to specify the name of the text file to which the User-Defined Data will be exported.

Comment

If you wish to enter a comment line preceding the user data that is appended to the text file, enter the comment here before pressing Export.

As Polygons

If the Data Class option is set to Lines/Polygons, each entry includes the commands Move To and Line To. Mark this option if you wish to export polygon commands instead (Poly Beg, Poly Point, Poly End). This can be used to create a closed polygon, rather than a collection of connected lines.

Export

Click this button to save the User Data to a text file. Once the text file is written, the User Data area is optionally cleared. In this manner, you can add a number of points, export them (which appends the data if an existing file is selected), add more points, export, and so on.