C2A can automatically download from the Internet catalogues of data and automatically integrate these into the maps displayed on the screen. Updating can be done at an interval specified by the user, or manually. To date, two dynamic catalogues are incorporated:
The command Dynamic catalogues… in the File menu lets you display the following dialogue box (Ctrl+F6 is a shortcut for this command):
The Display the catalogue check box lets you specify if the selected dynamic catalogue should be displayed on the maps. Note that simply selecting this option does not display the selected catalogue. You must also check the option Dynamic catalogues item in the Display menu (this command allows you to toggle the display of all the dynamic catalogues together).
The Highlight objects in the map check box lets you indicate that all objects in the dynamic catalogue must be specifically identified in the map. The objects in the ArasBeAM catalogue are indicated by grey discs behind the stars. The objects in the Exoplanet Transit Database catalogue are identified by blue discs. The following screenshot shows a few Be stars in a field where the current catalogue stars are not displayed (which is better to highlight the Be stars). These objects are labelled (through the menu: View / Object tags / Dynamic catalogues) to indicate the period of observation necessary for each object.
The following screenshot shows some stars from the Exoplanet Transit Database. These objects are labelled (through the menu: View / Object tags / Dynamic catalogues) to indicate the period of the exoplanet in days.
The Ignore the magnitude filter lets you ignore the current magnitude filter in calculating the postions of objects in the dynamic catalogue concerned, and therefore to display all the objects on the map. This is a handy option given the way these objects are used. Similarly the size of the discs representing the stars is exaggerated in relation to their magnitude so that they are more visible; this is the case for both the ArasBeAM and Exoplanet Transit Database catalogues.
For the Meteor Shower dynamic catalogue, the button Filter... gets accessible. It allows you to specify several options regarding the display of the metor showers in the maps. First you can decide if you want to display only the confirmed showers or not. You can also display the metor showers whose peak activity is in a range of specified dates. Finally, it is possible to request that the meteor shower class is displayed in the maps. A small colored square is associated with each meteor shower class: red for a meteor shower of the "Major" class, orange for a meteor shower of the "Minor" class, yellow for a meteor shower of the "Variable" class and green for a meteor shower of the "Weak" class.
The Automatic update every… lets you indicate at what interval the selected dynamic catalogue should be updated. Of course, an Internet connection must be available to make automatic updating possible. A value of 0 in this field indicates that automatic updating should not occur.
The Immediate update button lets you update without waiting for an eventual automatic update.
Once updating has been done, you must make sure that the display of dynamic catalogues has actually been requested (you must verify that the Dynamic catalogues item in the View menu is checked. You can also use the button for toggling the display of dynamic catalogues on the main toolbar). It is also possible to associate a distinctive mark with objects in dynamic catalogues. This is done simply by going to the Object tags menu of the View menu where there is a command Dynamic catalogues (see the screen shot above). The key combination SHIFT+Ctrl+F11 is a shortcut for toggling object tags.