Connect NexStar 8 SE with Stellarium and Tracking Celestial Object with It

Connect NexStar 8 SE with Stellarium and Track Celestial Objects

Celestron NexStar 8 SE can be controlled from Stellarium, which makes it easier to point the telescope at planets, stars, nebulae, and other objects from a computer. Stellarium does not replace a proper telescope alignment, but after the mount is aligned, it can send GoTo commands and show where the telescope is pointing on the sky map.

What You Need

  • Celestron NexStar 8 SE mount and hand controller
  • A computer running Stellarium
  • A suitable cable between the computer and the NexStar hand controller or mount
  • The serial or USB driver required by your cable
  • A stable power supply for the telescope mount

The exact cable depends on the hand controller version. Some newer NexStar hand controllers have a USB port. Older hand controllers usually require a Celestron serial cable and a USB-to-serial adapter. If using a USB-to-serial adapter, install its driver first and check which COM port or device name the operating system assigns.

Prepare the Telescope

Before connecting Stellarium, set up the telescope normally.

  1. Put the mount on a stable surface and level the tripod.
  2. Attach the optical tube and balance the setup as usual.
  3. Connect power to the mount.
  4. Enter the correct date, time, time zone, and location in the hand controller.
  5. Perform a normal NexStar alignment, such as SkyAlign, Two-Star Align, or Solar System Align.
  6. Confirm that the mount can GoTo an object from the hand controller before using Stellarium.

This step is important. Stellarium can command the mount, but the mount still depends on its own alignment model for accurate pointing and tracking.

Enable Telescope Control in Stellarium

Open Stellarium and enable the built-in telescope control plugin.

  1. Open Configuration Window.
  2. Go to Plugins.
  3. Select Telescope Control.
  4. Enable Load at startup.
  5. Restart Stellarium if required.

After restarting, open the telescope control panel from the toolbar or plugin menu.

Add the NexStar Telescope

In Stellarium’s telescope control settings, add a new telescope connection.

  1. Choose Add.
  2. Select the option for a telescope controlled directly through a serial port, or use ASCOM if you are on Windows and prefer the ASCOM driver route.
  3. Choose a Celestron NexStar-compatible protocol when available.
  4. Select the correct serial port.
  5. Set the serial speed according to the driver or telescope control option. If unsure, use the value recommended by Stellarium or the Celestron driver documentation for your setup.
  6. Save the configuration and start the connection.

On Linux or macOS, the port may look like /dev/ttyUSB0, /dev/ttyACM0, or another device under /dev. On Windows, it will usually appear as COM3, COM4, or similar. The number may change if the cable is plugged into a different USB port.

Slew to an Object

Once the telescope is connected, Stellarium should display a telescope marker on the sky map. To slew to an object:

  1. Search for a target in Stellarium, such as the Moon, Jupiter, M42, or a bright star.
  2. Select the object.
  3. Use Stellarium’s telescope slew command, often available through the telescope control panel or a keyboard shortcut configured by the plugin.
  4. Watch the telescope while it moves, and be ready to stop it if the tube approaches the tripod or another obstacle.

After the GoTo completes, center the object using the hand controller or Stellarium controls. For visual observing, final centering is usually best done at low speed through the hand controller.

Tracking

The NexStar mount handles tracking after alignment. Stellarium sends pointing commands; it is not the program that physically tracks the object second by second. If the mount is aligned and tracking is enabled, the telescope should continue following the sky after it slews to the target.

For better results:

  • Use a stable power source. Low voltage can cause strange slews and tracking errors.
  • Recheck time, location, and time zone if GoTo accuracy is poor.
  • Use a low-power eyepiece first, then increase magnification after centering.
  • Avoid cable tension while the telescope slews.
  • Do not let the optical tube hit the mount base or tripod legs.

Quick Troubleshooting

If Stellarium cannot connect, check the port first. Make sure the driver is installed and that no other program is using the same serial port.

If the telescope connects but points incorrectly, redo the NexStar alignment from the hand controller. Also confirm that Stellarium and the hand controller use the same location, date, and time.

If the telescope marker appears but does not move correctly, disconnect and reconnect the telescope in Stellarium, then restart the mount if needed.

If GoTo works from the hand controller but not from Stellarium, the issue is probably the computer connection, driver, port selection, or protocol setting rather than the mount alignment.

Summary

The basic workflow is simple: align the NexStar 8 SE with the hand controller, connect it to the computer, enable Stellarium’s telescope control plugin, choose the correct Celestron-compatible connection, and send GoTo commands from the sky map. Stellarium is especially useful for choosing targets visually, while the NexStar mount remains responsible for accurate alignment and tracking.

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