Cartes du Ciel (Planetarium)
Cartes du Ciel (CdC) is the planetarium tool Starship integrates with for target lookup and visual confirmation. Free, mature, and has a clean TCP server protocol.
Connection
CdC exposes a TCP server on port 3292 by default. Enable it in CdC: Setup → General → Server, tick "Server enabled", note the port (3292), then restart CdC.
In Starship, open Settings → Integrations → Cartes du Ciel and set:
- Enable planetarium — the master on/off switch. When off, nothing connects and the planetarium controls elsewhere in the app are inert.
- Host (IP or hostname) — the machine CdC runs on. Use
localhost(or127.0.0.1) when CdC is on the same PC as Starship, otherwise the CdC computer's address. - Port — CdC's server port (3292 unless you changed it).
Save and restart Starship for a host/port change to take effect. Starship talks to CdC over TCP, opening a connection for each request rather than holding one open, and quietly pings in the background so the connection indicator stays accurate.
You can confirm the link on the Console page: the planetarium status pill reads disabled (feature off), not connected (can't reach CdC — check it's running and the server is enabled), or shows host:port in green once Starship can reach it.
What we use it for
Sequencer target lookup. Select an object in Cartes du Ciel, then in the Sequencer click the ↩ CdC button on a target row. Starship reads whatever object is currently selected in CdC and fills the target's RA, Dec, and (if the row is unnamed) the object name — no local catalog needed. This sits alongside the ⌖ SESAME button, which resolves a name through the online CDS service instead; CdC is the offline, "point at it in the chart" alternative.
Resolve a named target at run time. In a blockscript target list, tick Resolve via planetarium on a target. Instead of storing fixed coordinates, Starship hands the target's name to CdC when the step runs, reads the coordinates back, and slews to them. Handy when you want the schedule to name targets and let CdC supply the numbers.
Highlight / send a target. Starship can push a target to CdC to mark it in the chart, either by name or by RA/Dec, so you get a visual sanity check of where the run is pointed.
What we don't use it for
CdC isn't a control surface for Starship. Sending a target to CdC only highlights it in the chart — it never moves your equipment. All slews go through the Console's mount control, gated by the Safety Supervisor; the planetarium is a coordinate source and a visual reference, nothing more. Starship also doesn't drive CdC's field-of-view, telescope markers, or imagery.
Future
A second backend (Stellarium, via its remote-control plugin) is on the roadmap. The planetarium backend is selectable in config (cdc today), so swapping or adding a backend is a settings change rather than a rebuild.