# FAQ

## General

How can I contribute to Cartes du Ciel-SkyChart?

You can contribute in several ways:

- Try the last development version and report the bugs you find to the bug tracker.
- Volunteer to write copy, or edit this text to solve spelling and grammatical errors.
- Translate the program, or this web text into your native language.
- Review the program code and propose your own improvements.
- Please send me your ideas, I am interested in your suggestions.

## Installation

I have Cartes du Ciel-SkyChart version 2.76. What do I need to do to run the new version 3? How many files do I download and do I delete 2.76 first?

You just need to install the version 3.0 for Windows in the same directory as the version 2.76. Do not try to install in another directory, and do not delete anything because you can use the two versions at the same time. This is useful to validate that the V3 work fine for you. Run cdc.exe for the V3.0 or ciel.exe for the V2.76

Are the earlier catalogs associated with CdC V2.76 compatible with Cartes du Ciel-SkyChart V3 ?

Yes, all these catalogs can be used with the version 3.0. The only exception is the external catalog, they are replaced by the more convenient Catgen text catalog or the Virtual Observatory catalog.

Where do I install the extra catalogues under Linux, in which directory do they go into?

If you have root permissions, it is best to put them in /usr/share/skychart/cat to have them with the basic catalogs. But you can also install them anywhere as long as you specify the full path in the catalog configuration menu.

Can I get Cartes du Ciel-SkyChart software for a Macintosh?

Yes, the version 3 now work the same on Mac OS X than on Windows or Linux. Look at the specific installation instruction for more information about the additional software you need to pilot a telescope or compute the artificial satellites.

What can I do with MySQL?

MySQL was used as the default database up to the version alpha 7. Since June 2005 it is replaced by the more simple SQLite. You can still use MySQL if required, for example to share the database across a local network. The database is used to store the following data: asteroids and comets elements, object pictures and world locations.

## Usage

Does Cartes du Ciel-SkyChart V3.0 for Mac/Linux support telescope tracking?

Yes, Cartes du Ciel-SkyChart V3.0 can use INDI to interface the telescope. Any telescope model supported by INDI must work with Cartes du Ciel-SkyChart. Also you can use the include interface for Meade/LX200 protocol or a simple encoder interface.
The ASCOM standard is specific for Windows and can be run only with this platform.

There is no “follow” and “see” telescope in the telescope menu of the V3.0?

There is now a Track telescope entry in the Telescope menu
You can also use the “lock on” feature (the anchor button). When the telescope is connected and no other object is selected, this button locks on the telescope.

Why is the sky blue?

Because it is daytime or the Moon is up. You can change that from the configuration menu, Display → Sky colour. Or change the date / time in the program by Setup → Time. Or change the coordinates system from Alt/Az to one of the other systems by a click on one of the icons on the left bar in the Coordinates system group

How can I see a sky chart with simulation of the planets before 3000 B.C?

Since the version 3.9 you can use the JPL ephemeris DE431 that extend the computation range for the planet to -13000 → +17000.

How can I switch the language from English to my language?

The language is normally detected automatically when you start the program. The menu Setup → General → Language gives you the opportunity to select another language.

Does Cartes du Ciel-SkyChart V3 have DDE support?

No, the standard communication protocol for the V3 is TCP/IP for portability reasons.

Why are the the fonts with my Linux version too small / too big?

There was a problem about Gtk1 font settings on Linux in the past. In the latest versions of Skychart, Gtk2 is used by default. There should not be such a problem now. If so, please report the bug to us.

## Common Problems

I've installed CdC V3.0 but program doesn't display stars or objects.

Maybe you have only installed the program. You also have to install the base catalog package, it is normally include with the standard download. Look at Download page and follow instructions in the Installation of extra catalogs.
Are your star catalogs activated? Make sure they are, see the Stars tab from the Setup → Catalog dialog. Another possibility is that you accidently switched the display of stars off. Check the possibillity of the icon in the object group A of the object bar.
Or maybe the cause is hidden in a troubled display filter. Check your settings in the tab Object Filter from the Setup → Chart, Coordinates dialog.