What is a device used by sailors to navigate by using the sun and the stars?

Sailors use a sextant to navigate by measuring the angle between celestial bodies, such as the sun and stars, and the horizon. This instrument allows them to determine their latitude and longitude, which is essential for charting their course at sea. By taking observations at specific times and using astronomical tables, sailors can accurately pinpoint their position. The sextant has been a critical tool in maritime navigation for centuries.