The last two versions of C2A for Windows are available for download in case of a regression. It is advised to install the latest version.

Most recent Version

New features in version 2.0.27
Problem fix: C2A now checks that the orbital elements fields from the MPC are not empty. En error in the MPC format (empty semi major axis) was inducing a crash in C2A when positions were displayed after the orbital elements were imported.
Problem fix: syntax in the VizieR USNO-B1.0 query has changed. The field names e_RAJ2000 and e_DEJ2000 must be used in place of e_RAdeg and e_DEdeg. The protocol syntax change is now taken into account into C2A.
Problem fix: a double click in an empty element of the user or observation image list was crashing the application.
Problem fix: when Equinox was changed into the planetary position options, this change was not immediatly taken into account.

Version Before Latest Version

New features in version 2.0.26
When C2A is launched from the Occult Watcher software, one checks if a previous instance of C2A is already running. If it is the case, and if the correct option is set in the C2A Add-in options, the existing instance of C2A is used to display the occultation map. Version 0.44 of the C2A Add-in for Occult Watcher is required to benefit from this option.
An option has been added in the C2A Add-in for Occult Watcher in order to force the display of the NOMAD catalog whatever is the catalogue referenced in the occultation event (Tycho-2, Hipparcos, UCAC2, ...). Version 0.44 of the C2A Addiin for Occult Watcher is required to benefit from this option.
A tool has been added (command "User Images & Obs..." in the "Images" menu) that allows the user to easily manage and access its own images and observations under the form of a list.
A problem has been fixed with the decimal separator in the case some particular Windows Regional Settings were used (e.g. German (Swiss)).

In order to install the C2A for Windows distribution on your system, extract the contents of the ZIP archive in a temporary directory and run the setup.exe executable. Then simply follow the installation steps as displayed on the screen. Please be aware that the Windows installation procedure (but nor the software itself) is in French, which should not be a problem considering it is a very basic installation.

If a previous version of C2A for Windows is already installed on your system, uninstall it first using the Windows Configuration Panel. Then install the new version. Your settings will not be lost.

Polynome File to Compute Planetary Positions between 1900 and 2100

UCAC2 Bright Star Supplement

Add-in to Use C2A with Occult Watcher

Pre-release 0.44
Size is 7 kBytes

Occult Watcher is a software designed to easily manage predictions of star occultation by asteroids. An Add-in is available to directly launch C2A from Occult Watcher and display a map of the occultation (setting automatically the time, location and catalogue for the considered event). The Hipparcos and UCAC2 catalogues are often used in occultation predictions, so it is necessary to have them installed on your computer before using this Add-in. See the Catalogues page to download the Hipparcos catalogue and the Tools page to get the UCAC2 catalogue compiler for C2A.

Caution! In order to use this C2A Add-in for Occult Watcher, you need at least version 2.0.26 of C2A and the most recent version 2.5 Beta 1 of Occult Watcher.

To install the Add-in, simply extract the file OccultWatcher.C2a.dll (available in the ZIP file) and copy it into the Occult Watcher installation folder. A C2A entry will then be added in the Occult Watcher Add-in menu. To launch C2A and get the map of an event, select this event in the Occult Watcher list and go into the "Add-in" menu to create the C2A Occultation Map.

New features in version 0.44 are the following:
A single instance of C2A is used to display maps.
NOMAD catalog usage can be forced trhough an option in the Add-in.
French and English are the two supported languages (language is set through the Occult Watcher Help menu).