Celestron StarSense Explorer LT 70AZ

The Celestron StarSense Explorer LT 70AZ is designed to make getting started in astronomy as straightforward as possible. It combines a conventional 70mm refractor telescope with Celestron’s StarSense Explorer technology, which uses the camera in your smartphone to recognise star patterns and determine where the telescope is pointing.

Once the smartphone has been aligned with the telescope, the StarSense Explorer app can show you which celestial objects are currently visible and guide you towards your chosen target. On-screen arrows indicate which way to move the telescope, and the bullseye turns green when you have reached the target position. The telescope itself remains entirely manual, so there is no motor or computerised mount to operate.

The 70mm refractor has a 700mm focal length and a focal ratio of f/10. Celestron specifies fully coated glass optics and a useful magnification range from 10x to 165x. Two eyepieces are supplied: a 25mm eyepiece providing 28x magnification and a 10mm eyepiece providing 70x. A 2x Barlow lens is also included, allowing these eyepieces to be used at higher magnifications when conditions and the target permit.

The manual altazimuth mount is simple to move and includes an altitude slow-motion adjustment with a sliding rod. This makes it possible to make small pointing adjustments and follow an object as it appears to move across the sky due to the Earth’s rotation. The telescope is mounted on a full-height adjustable tripod with an accessory tray.

The StarSense Explorer system can be particularly useful when learning your way around the night sky. Celestron states that the telescope can be used to observe objects such as Jupiter, Saturn, Venus, the Orion Nebula and double stars from a city location, with more objects becoming visible from darker skies.

The supplied 90-degree erect-image diagonal also makes the telescope suitable for daytime viewing of subjects such as birds, wildlife and landscapes. A StarPointer red-dot finderscope is included as an alternative to using the smartphone-based StarSense Explorer system.

The complete kit weighs 3.35kg, making it a relatively easy telescope to transport to a darker observing location. No separate power supply is required for the telescope or mount, although Celestron recommends an external phone power source if additional phone battery capacity is needed while using the StarSense Explorer app.