Find Polaris or Sigma Octantis
See the information needed to locate the pole star quickly and get your mount pointed in the right direction.
Astro Locator
Get polar aligned quickly.
Astro Locator is a polar alignment app for iPhone that helps astronomers find Polaris or Sigma Octantis, level an equatorial mount, and set elevation quickly.
Requires iOS 18.0+
Why It Exists
Built for fast telescope setup.
Astro Locator is designed for astronomers who set up and break down each session and want a fast, reliable way to get roughly polar aligned before fine adjustments for observing or astrophotography.
Core Features
Everything needed for a fast field setup.
Set mount elevation and heading
Use the device sensors to level the mount, check heading, and match mount elevation to your latitude.
Check time during setup
Check UTC and local time during setup so your mount alignment and imaging workflow stay consistent.
Plan around twilight
See sunrise, sunset, and astro twilight timings so you know when viewing and imaging become practical.
Both Hemispheres
Works in both hemispheres.
Use Astro Locator whether you are aligning with Polaris in the northern hemisphere or Sigma Octantis in the southern hemisphere. The app is built to support both workflows clearly.
Reviews
What Users Say
Great app for new equatorial mode on Seestar S50. It lets you set up in twilight or daylight and then only need minor tweaks once it is dark.
This really makes setting up my scope quite simple.
FAQ
Frequently Asked Questions
Getting Started
How do I use Astro Locator to find Polaris?
Polaris workflow:
- Use Astro Locator to find north and check that Polaris and your target path have a clear view.
- Level the mount by placing the iPhone on the mount and adjusting the legs until the elevation reading sits at 0.
- Roughly align the mount north by placing the iPhone against the side of the mount or along the OTA until the compass reads 0 or N.
- Rest the iPhone on top of and in line with the OTA and raise elevation until it matches your latitude.
- Polaris should then be visible in the polarscope for fine adjustment.
How do I use Astro Locator to find Sigma Octantis?
Sigma Octantis workflow:
- Use Astro Locator to find south and check that Sigma Octantis and your target path have a clear view.
- Level the mount by placing the iPhone on top of the mount and adjusting the legs.
- Roughly align the mount south by holding the iPhone against the side of the mount.
- Rest the iPhone on top of and in line with the OTA and adjust elevation to match your latitude.
- Sigma Octantis should then be visible in the polarscope for fine adjustment.
Features
Does Astro Locator use True North?
Yes. Astro Locator uses True North.
Troubleshooting
Why does Astro Locator ask for location authorisation?
Astro Locator requires authorisation to access your location in order to function correctly.
Enable it in Settings > Privacy & Security > Location Services > Astro Locator > Allow Location Access “While using the App”.
Download
Astro Locator for iPhone
Available on the App Store for iPhone.
Requires iOS 18.0+