Description
Celestaire Astra III Professional Commercial Edition – Split Horizon Mirror is the top model in the Astra series and designed for professional use, teaching and intensive training in astronomical navigation. Combining high precision, solid construction and good ergonomics, this sextant is an advanced instrument for serious sextant navigation.
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, it allows you to calculate your position at sea without the use of GPS. Even in the age of modern electronic navigation, the sextant remains an important backup instrument for long-distance sailors and a key tool in teaching astro-navigation.
Astra III Professional is a further development of the well-known Astra IIIB, one of the world’s most widely used metal sextants. The Professional model features a precise bronze arc fused to a lightweight aluminum frame. Bronze can be produced with a higher tolerance than aluminum, resulting in more stable scale and higher precision. At the same time, the aluminum frame keeps the weight down so that the sextant is comfortable to use during longer observations.
The extra weight in the bronze arc gives the instrument good balance and stability during observation. The model also has an improved and more ergonomic handle for better comfort and control when using the sextant in practice.
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 is clear glass so that the horizon is seen directly through the mirror. Many experienced navigators prefer this solution because it provides a very 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 AA batteries in the handle. This makes it possible to read the instrument in low light conditions, for example when observing stars at dusk or night.
The mirrors are carefully tested for high optical quality, and the instrument is designed so that the horizon mirror can be easily switched between split and whole-horizon type using two screws. This makes the sextant flexible if you want to change the mirror type later.
Celestaire Astra III Professional has a documented precision of ±15 arc seconds throughout the arc, making it suitable for both teaching and professional navigation. The model has also been selected by NASA for testing on the International Space Station (ISS) as part of astronomical navigation research.
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 precision sextant sailing instrument used by long-distance sailors, navigation enthusiasts and maritime institutions.
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.
