Description
Celestaire Astra III Professional Sextant – Split Horizon Mirror is a precise and robust metal sextant designed for serious astronomical navigation at sea. The model combines high accuracy, good balance and solid construction, and is used by long-distance 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. With the help of nautical almanacs and tables, you can then calculate your position at sea without using GPS. Even today, astronomical navigation is an essential skill for sailors who want an independent backup to electronic 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, giving a more stable scale and higher precision in measurements. At the same time, the aluminum frame keeps the weight low so that the sextant is comfortable to use during longer observations.
The extra weight in the bronze arc gives the instrument excellent balance and stability during observations. The model also features an improved and more ergonomic handle for better comfort and control during use.
This version comes with Split Horizon Mirror, the traditional mirror solution used on most classic 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 image of the horizon during observations.
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 conditions, such as star navigation at dusk or night.
The mirrors have been carefully tested for high optical quality, and the sextant is designed so that the horizon mirror can be easily switched between split- and whole-horizon type using two screws. This makes it easy to customize the instrument to your own preferences or use in teaching.
Celestaire Astra III Professional has a documented precision of ±15 arc seconds throughout the arc, making it suitable for both practical navigation and professional training. 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 reliable 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.
