Why mount slews to the wrong position in the sky?


Make sure your mount have sufficient power to make the slews. Power is one the primary problems faced by users but it is one of the least issues users suspect or investigate, so make sure to rule out power as the cause for the mount erratic behavior.


GOTO mounts learn how to go to specific objects in the night sky after they are properly calibrated and aligned at power up.

All mounts must be first aligned using the handset using 2 or 3 star alignments before you can use them with StellarMate. The only exception to this rule is as following:

  • EQMod: When using Skywatcher mounts with EQMod driver, no alignment is necessary at startup. It should start pointing at the celestial pole (unless custom parking position is used). Make sure the mount is powered up while it is in the Home Position. Afterwards, slew to a nearby star and use Ekos Alignment module to sync the telescope. EQMod would then be ready to make accurate GOTOs.

      home position

  • Hibernation: For mounts that support hibernation (e.g. AVX), it is possible to hibernate and later on wake up the mount without losing alignment data.

Time & Location

This is the most common cause for inaccurate and erratics GOTOs. StellarMate requires an accurate Time and Location data in order to drive the mount correctly. If you are using Ekos on a PC/Mac, KStars would automatically set the mounts time and location. You can double check the mount time and location settings by going to INDI Control Panel --> Mount Driver Tab (e.g. EQMod Mount) --> Site Management Tab.

site management

However, this only sets the mount time (in the handset) and not the StellarMate System Time. The system time is still important for other calculations, so it is prudent that StellarMate system time is accurate. StellarMate gadget is shipped with a Real Time Clock (RTC) module that keeps the system time even when the unit is turned off. If you are using StellarMate OS on a plain Rasbperry Pi board, then there is no way to keep the time ticking and accurate. StellarMate would sync the system time once it has an active connection to the internet.

In case you are using StellarMate in HotSpot mode, the unit has no access to the internet and the time must be either it Manually via VNC or via the StellarMate App. When using the StellarMate App, it would automatically syncs StellarMate system time and location when it establishes communication with the unit. The time and location information are extracted from your phone/tablet. To explicity sync the GPS information, click on the Sync GPS button in the app.

stellarmate sync gps

If you are using a GPS dongle in StellarMate, then it would be sufficient to sync the StellarMate system time and location once powered up. Without the GPS dongle, using the StellarMate App is the next best option as it always keeps StellarMate system time and location synchronized with your phone/tablet.

Mount Model

When using EQMod mount or any mount that uses INDI Alignment Subsystem, it improves its GOTO accuracy by building a model of the night sky in the driver itself. This is in contrast to traditional mounts when the model is built in the handset (e.g. Meade). Sometimes the model inadvernetly lead to wrong GOTOs and you keep adding more sync points to correct this issue, it might end up getting worse. The best thing to do in this situation is to follow these steps:

  1. If the mount is not already unparked, unpark it (click the green flag in the toolbar).
  2. Go to Ekos Mount tab, and click on Purge all configuration. This will clear all settings related to the mount. ekos purge mount config
  3. Disconnect and Stop Ekos.
  4. Power off the mount.
  5. For equatorial mounts, if the mount is not pointed at the celestial pole with the weights down, adjust it manually until you reach this position. For Alt-Azimuth mounts, make sure the mount is in its home position.
  6. Power on the mount.
  7. Start the Ekos equipment profile again.

Now, depending on the mount type, it should have the correct startup position:

  • EQMod: Mount should point toward the celestial pole and a new default parking position is recorded
  • Other: Mount should point toward the last alignment star that you used in the handset when performing the initial 2 or 3 star alignment process.

When performing GOTOs, the mount should slew normally and track.


If you still have issues after performing these steps, please open a ticket in the support area.

Please make sure to submit the logs required to investigate your issue. Turn on INDI + Mount logging and send the logs to support.