For a long time I was a user of Stellarium – however, I wouldn’t say I was using it to its full potential. I struggled with its quirky interface, and didn’t quite get to grips with the requirements to connect it to my mount and scope. Stellarium is resigned to my phone these days. Enter stage left, Cartes du Ciel / Sky Charts.
Cartes du Ciel (or CDC, as it’s also known amongst friends) is a gem of a program that helps you navigate the night sky. When teamed up with an ASCOM controlled mount, you will be able to click on objects from stars, to planets, to deep sky objects (DSOs) such as galaxies and nebula, and get more information on them and allow your mount to then move in that direction to centre on that object.
What You Need
- Laptop or PC (whilst CDC works with Windows, Mac, Linux and FreeBSD, we are assuming just Windows here to take advantage of ASCOM)
- A correctly configured ASCOM Platform and configured mount with EQMod
- Cartes du Ciel Sky Charts downloaded and installed
How To Do It
- Load up CDC. You’ll be presented with a Sky Chart.
- To configure CDC to use our ASCOM controlled mount, go to the Telescope menu and select Settings…. Ensure that ASCOM is selected.
- Click OK to return back to the Sky Chart view. Now to connect CDC to our ASCOM mount go to the Telescope menu again, this time select Connect telescope… This loads up the following screen
- To tell ASCOM which configuration of EQMOD we’re using, we select the Select button. This will load up the following dialog box. You will see the profile name that we created when previously setting up ASCOM.
- Click OK to confirm that’s the correct profile to return back to the previous window.
- We simply now press the Connect button. This then loads up that familiar EQMOD control dialog box and change the status from red to green in the telescope control box in CDC:
- You’ll see that our mount starts off in the “Parked” position. In this position you won’t be able to move the mount using the controls. So press the Unpark button before we can continue.
- At this point, we can click on objects in CDC and get more information on them. For example, clicking on M81, then on the M81 label will bring up the following information about that object:
- Click on Close to close the dialog box. Now, to get the mount and scope to move to that position in the sky, we right click on M81 and choose Telescope > Slew M81
- If all is well, your telescope will now move around to point to M81. Verify by looking through the eyepiece or through a program like SharpCap if your cameras are connected. It could be that they’re not quite centred in the view. To correct this, use the EQMOD onscreen controls to move your scope so that the object is centred on screen (Tip: you can adjust the speed of movement using the drop down found in the slew controls. The default setting (1) is for minute adjustments. I find using the default set under (3) gives a good nudge in the right direction).
- When it is centred, we can tell CDC that this is actually where that object is. Right click on M81, but this time choose the Telescope > Sync M81 option. This will ask for confirmation that what you’re seeing is M81. Select OK and CDC positioning will update.
That’s it – so congratulations! We can now use CDC to navigate the night sky and our telescope and mount will follow!
What We Did
Using Cartes du Ciel (CDC) to control our mount to position in the sky is a must have addition to our astrophotography toolkit. It allows us to concentrate on the image capture of astrophotography and less about navigating to try and find feint fuzzy objects!
By utilising our ASCOM EQMOD set up that we configured earlier, we tell CDC it is there for use. We make sure the correct profile for our mount is selected and then we basically just connect the mount using CDC – it’s that simple.
We can then select any of the objects on screen, get more information about them, and crucially, get our telescope and mount to point to that object in the sky. If things aren’t quite centred, we can manually adjust the object into view (using the onscreen controls) and then sync this position with CDC.