Description
Celestaire Astra III Professional – Split Horizon Mirror is a precise metal sextant designed for serious astronomical navigation at sea. Combining high precision, good balance and solid construction, this model is an advanced instrument for sailors, navigation enthusiasts and sextant navigation courses.
A sextant is used to measure the angle between a celestial body – such as the sun, moon or a star – and the horizon. Together with nautical almanacs and tables, you can calculate your position at sea without using GPS. Astronomical navigation is still used both as a backup to electronic navigation and in teaching classical navigation.
Astra III Professional is a further development of the well-known Astra IIIB sextant. The main difference is a precise bronze arc mounted on a lightweight aluminum frame. Bronze can be manufactured with a higher tolerance than aluminum, resulting in a more stable scale and higher precision in measurements. At the same time, the aluminum frame keeps the weight low so that the instrument is comfortable to use during longer observations.
The extra weight in the bronze arc gives the sextant excellent balance and stability during observation. The model also has an improved and more ergonomic handle that makes the instrument comfortable to use in practice.
This version comes with Split Horizon Mirror, the classic mirror solution used on most traditional sextants. One half of the horizon mirror is reflective, while the other half is clear glass so that the horizon is seen directly through the mirror. Many experienced navigators prefer this solution because it provides a natural and precise view of the horizon.
The sextant is equipped with LED illumination of the arc and micrometer drum, powered by two standard AA batteries in the handle. This makes it possible to read the instrument when observing in low light, for example during star navigation.
The mirrors are carefully tested for high optical quality and the sextant is designed so that the horizon mirror can be easily switched between split and full-horizon type using two screws. This makes it easy to customize the instrument to your own preferences.
Celestaire Astra III Professional has a documented precision of ±15 arc seconds throughout the arc, making it well suited for both practical navigation and teaching. The model has also been selected by NASA for testing on the International Space Station (ISS) in connection with research on astronomical navigation.
The sextant is delivered in a sturdy lacquered wooden box and includes telescope, solar filters, instruction book, certificate of accuracy and adjustment tools.
This is a precise and robust sextant for sailing, used by long-distance sailors, navigation enthusiasts and maritime training environments.
Production
Celestaire sextants are manufactured by Changzhou Celestaire Instrument Co. in China to Celestaire USA specifications and quality standards. Each sextant comes with a certificate of accuracy and in a protective lacquered wooden box with instruction manual and adjustment tools.
Navigasjonsbutikken Kart.no AS is a distributor of Celestaire in Norway. For schools, courses and institutions, we can also deliver larger batches of sextants – please contact us for price and delivery time.
